What is Helicon Filter? Helicon Filter is a set of unique and easy-to-use tools for enhancing images from digital cameras. Helicon Filter is designed for amateurs and advanced photographers who want to obtain high quality images without spending too much time. Helicon Filter includes the most popular operations from professional workflow: - noise reduction - red eye suppression - chromatic aberration suppression - geometric distortion and vignetting correction - sharpening - brightness management and levels - color adjustment and advanced black and white conversion - crop with rotation and resize - text and frames - full set of retouching brushes

Versions

Helicon Filter is released in two versions: Home and Pro. After thirty (30) days of evaluation period both editions switch to Free mode.
Please see the comparison table below:

Licensing

Helicon Filter in Free mode can be used without limitation.

Helicon Filter Home and Pro are shareware programs.  After thirty (30) days of evaluation period both versions switch to Free mode. More details at home page (http://www.heliconfilter.com/).

The updates for registered users are free.

You can buy a license online by following the instructions on the product home page.

Please see the detailed instructions here: http://www.heliconsoft.com/filter_help.html

Download

Open program home page http://www.heliconfilter.com and follow the link to the download page

System requirements

The recommended system configuration to process a 4-5-megapixel images is:

• Windows 2000, XP, Vista, Vista x64
• 3000 Mhz or higher
• 1024 MB RAM or higher
• True color display, resolution 1280x1024 or more

Minimum system requirements are:

• Pentium-III class machine
• 256 MB RAM
• Hi-color display, resolution 800x600

Installation

Start installation program and follow instructions.

Registration

On 30th day of evaluation period all features of Helicon Filter are activated in all versions (Home, Pro, Free).
 

• To use advanced features after evaluation period, one should purchase a license from our web site  (http://www.heliconfilter.com/).
• After that you will receive an activation code.
• Press Registration button in the toolbar and enter activation code to unlock the program. More information you will find here: http://www.heliconsoft.com/registration_help.html
  

Recommended workflow:

1. Open an image

2. Set up filters

3. Save the result

The tabs represent the usual workflow of a digital photographer. 

1. You are now on the Source tab. Open the image by clicking it in the list on the right.
2. Switch to the next tab and adjust image with the tools of the selected filter (see sliders on the right).
3. When you are satisfied with the result, switch to the next filter by clicking on the appropriate tab (e.g. Colors, Frame).
4. Switch to Save tab. The program will apply all filters that you set up. From the Save tab you will be able to save, print, email the final image.

When processing the file in the Helicon Filter, you always see the set of tabs with filters that can be applied to the source image to get the image that will be saved.

Тhere are two special tabs with the bold names. The Source tab let you see the original image and other files in the same folder .
Switching to Save tab makes the program apply all the filters to the source image and show the final result.

From the  Save tab you can switch back to filters to adjust settings and apply them anew. If you are satisfied with the result, you can save image to disk, send by email and so on. For more options please read about the Save tab.

Customizing the set of filters

The program has an advanced set of filters that solve typical problems of digital photographer.  By default all filters are enabled.

To show or hide some of the filters please use menu item "Filters\Personal workflow settings\". For example you can exclude "Distortion" filter if your camera or shooting conditions allow to make photos without geometrical distortions and vignetting.

Applying individual filters

You can apply any filter in any sequence calling them through the "Filters" menu item. For example you may resize the image and then apply the sharpening. Or you can apply Frame filter to add two different texts on the same image.

To call the second filter please go to the Save tab first. Otherwise the current filter will be ignored.

When you call the filter from the menu, the program is not sure which image should be processed - the original or the result of the previous operation. So the program asks you to choose the image. Normally it should be the result.

Opening another image

If you finish to process the image and you want to process the other one, you can do it in three ways.

1. If image is in the same folder: Switch to the Source tab and click the file from the thumbnails of the navigation panel (on the right).

2. If image is in the recently used folder: Switch to the Source tab and open one of the recently used folders () there.

3. If image is in some other folder:  Switch to the Source tab, open folder tree ()  and browse the folders there.

You can always use   "File\Open..." menu command.  If the file contains EXIF information, then it will be shown just below the image preview.

Helicon Filter Home and Pro edition support JPEG, TIFF, BMP, PSD and various RAW formats with 8 and 16 bits per channel.

Helicon Filter Free opens the same types of files but can write only JPEG and BMP files.

It is also possible to paste an image from the windows clipboard. This is not available in Free mode.

Adding voice and text comments to the image

Press on the comments icon () in the toolbar or use menu\Edit command to open Voice and text comments dialog.

You can record, play and delete existing voice comments by appropriate buttons.

Additional parameters such as sound quality or volume level can be set in the Preferences.

You can also add text comments which will be save in IPTC field. You cannot add text comments to files which format does not support IPTC (BMP, RAW, GIF, PNG).

Text comments are shown as tooltips when you place mouse pointer over the image in navigation panel  on the  Source tab.

Batch processing of multiple images 

Helicon Filter let you apply the same settings to all or only selected images in the folder. Please see more information here.

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Navigation Panel

The Navigation panel shows the thumbnails of images in the current folder. You can activate the navigation panel using View->Navigation panel menu command. You can perform the following operations in the navigation panel by right clicking the image or by pressing on a menu icon (): Select all command marks all images in the folder. Unselect all command clears all marks, none of images becomes selected. Invert selected command changes a state of the image to the opposite (selected->unselected, unselected->selected).  Command Add selected to queue images adds marked images to the queue with the current settings. Rename selected command  lets you rename one or a group of files using template. For example, you can rename all your files this way: "2005.06.25-The Beach (13)", so that your files are always shown sorted by date. Copy selected command copies the marked files to the selected folder. Move selected command moves the marked files to the selected folder. Delete selected command moves the marked files to the trash-bin. Lossless rotate commands rotate the image and save it with the original date and time. The operation is lossless so JPEG quality does not deteriorates. RAW files cannot be rotated by this function. Auto rotate (lossless) command analyzes the image and tries to define its orientation. The command  assumes that the upper part of the image should be brighter than the bottom part. The program checks only images in original "landscape" orientation and ignores already rotated images. Refresh list command updates the thumbnails and can be useful if you delete or rename files outside of the program manually. Recent folders  command (available from a navigation panel toolbar ) remembers the list of last folders from which the image was open. Folder tree  command (available from a navigation panel toolbar ) opens a list with a folder tree so you can see where you are located now and choose another folder. Parent folder  command (available from a navigation panel toolbar ) lets you jump to the parent folder. All marks in the current folder will be lost.

Noise Reduction Tab

Please note that the noise reduction filter is not applied on the tabs where downsized  images are used for faster preview (Brightness, Color, Distortions, Frames tabs). 

To apply all filters and see the final result please switch to the Save tab. If you like the result, you can save it and process the next image. If you don't, you can always switch back to the filter, fine tune the settings and get an updated result.

The program remembers the settings for each file you processed. So when you open the file again, the program recalls the most recent settings for this file. You can also save the file settings manually (Menu->Settings->File Settings).

Pop up menu

Pop up (or local) menu is available by left clicking on the image.

Adjust noise sliders:  The noise level under a cursor will be measured and the appropriate slider (highlights, general noise level or shadows) will be adjusted. You can use small, medium or large area for measurements. Use small area unless you need a very precise noise estimations to compare a noise level of several images. Increase (Decrease) noise reduction for this color range commands let you change noise reduction for a given (i.e. clicked) color  by 50%. You can use this feature to make noise reduction more selective. For example, you can increase noise reduction for the sky to clear all noise, and decrease noise reduction for the forest to keep it from smoothing. Use the Noise Map button to analyze the results more precisely. The same commands can be accessed through the "Tools" toolbar on the tab. Instead of a right clicking the image and selecting the command you can choose a tool (e.g. "Adjust noise sliders") and then click the image to apply the command.

Please have a look at the example below. The water and trees have almost the same level of details, so the program cannot find where the noise and the texture are. For the image on the right, noise reduction was decreased for the color range of the trees.

Original image (coastline of a lake)

Denoised image (the trees are blurred)

Selectively denoised

To open noise reduction equalizer use appropriate button on the noise tab. Equalizer lets you define a noise reduction level for every hue in your image. Usually higher noise reduction levels are set for skin tones and the sky with lower levels set for green. Sample print screen on the right illustrates this case. Use Noise Map button to analyze the changes more precisely. To change the equalizer curve simply click on the equalizer at the point that the line is to be raised to and the line will “jump” up to the cursor, then drag left or right to widen the affected color range. Right Click anywhere on the Equalizer is to reset the line to “straight”. White vertical line shows you a hue of the area under the mouse cursor. Black line shows the hue under the last click.

Defects and artifacts

The Add or change map files button opens an appropriate tab in the Preferences of the program. There you can define dust/dead pixels maps for every image resolutions.

Please note that sometimes RAW files and JPEG files have difference resolutions. In this case you will need to create maps for RAW and JPEG images separately.

The Filter hot/dead pixels  checkbox makes the program use earlier defined map to mask dead pixels.  This option is available only if you previously defined a map for resolution of the current image. To create the map of dead pixels please close an objective and make a shot. Normally dead pixels will look like bright points on the black background.

The Filter sensor dust  checkbox makes the program use earlier defined map to mask sensor dust.  This option is available only if you previously defined a map for resolution of the current image.

To create dust map please follow through the steps:

1. Set your camera to a manual mode.
2. Set aperture to 8. The dust is practically not noticeable at low apertures (2.8-4)
3. Point your camera at a white sheet of paper or at the sky. The image should not contain dark areas.
4. Unfocus the camera. Otherwise dots on the paper or  birds in the sky will be interpreted by the program as dust points.
5. Make a shot. Repeat for each resolution your usually use. Make a shot in RAW if your RAW files have different resolution from JPEG files.
6. Add dust maps with     button.

Here is an example of the dust map usage (crops, courtesy of Peter Borschberg):
 

Original image

Dust map

Filtered image

Tip: you can apply dust filtering to all your images in a batch mode. To do so, please do the following:

1. Reset all using button on the toolbar. All tabs will have gray points on them, which mean that no filter is applied.
2. Go to Noise tab and enable it.
3. Set Noise level slider to 0 to disable noise removal.
4. Set Filter sensor dust checkbox to activate dust filtering. Make sure that you have already loaded dust maps for all image resolutions.
5. Call menu command "Queue/Add current folder"
6. In the appeared Queue dialog set up parameters (folders, formats, quality) and start processing.

Tip for advanced users: you can also save the settings above with a menu command "Settings/File settings" and then apply them to selected images on the Source tab (Right click the image and select  "Apply preset and add to queue" command).

Simple mode

If you prefer an easier method – switch to Simple Mode. Click on View, then Simple preview mode. Or Click on the button on the toolbar.

Hints and Tips

• Noise looks worse on a monitor screen than it does when printed.
• Noise is noticeable on homogeneous areas (i.e. sky), and is hardly visible on textures (i.e. foliage).
• Images with too much noise reduction look unnatural (plastic).
• Do not spend too much time on a fine tuning - nobody will notice the marginal improvements.

Recommended workflow

General workflow

• Press a reset () button to set all options to defaults
• Shift-right-click on the remaining noise to adjust automatically the sliders (or right-click> popup menu> Adjust noise sliders). Repeat for each color that needs additional noise reduction.
• If noise is too strong, click on High noise (next to Method) and increase the Radius value.

Selective noise reduction.  If you want to change a noise reduction level for specific objects/areas (i.e. skin, sky, green), use Noise reduction equalizer and Color ranges tool.

• Click on the Noise Map button to see a noise reduction level in the areas you are interested in.
• Equalizer: position mouse cursor over the target object and remember the position of this color on the equalizer by right clicking. Drag the curve up to increase noise reduction or down  to decrease noise reduction for the given color/hue.

Using Color ranges:

• If the equalizer is not selective enough (i.e. affects not only target object), use Color ranges instead.
• Color ranges: right-click the object and select "Increase (Decrease) noise reduction for this color range" command. You can apply this command several times to the same color to increase effect.
• To undo all color range changes Click the Reset Ranges button under the Equalizer button. To undo only the last change, click the “arrow” to the right of the Reset Ranges button

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Brightness Tab

This tab offers you a full set of controls to adjust the colors of your image.  Please note that most sliders produce non-linear effects.  That enables you to apply very strong effects without visual degradation of the image.

Please note that  some slow filters are ignored on this tab for faster preview (Noise reduction, Sharpening, Chromatic aberration, Retouching). 

To apply all filters and see the final result please switch to the Save tab. If you like the result, you can save it and process the next image. If you don't, you can always switch back to the filter, fine tune the settings and get updated result.

The program remembers the settings for each file you processed. So when you open the file again, the program recalls the most recent settings for this file. You can also save the file settings manually (Menu->Settings->File Settings).

About histograms:  For better understanding how each control works, please look at the histogram on the brightness equalizer. Histogram shows distribution of pixels by luminosity. The histogram can be represented by 256 columns. For example, column #0 on the left shows the number of pixels with luminosity 0. Column #255 on the right shows the number of pixels with luminosity 255. If you see a "hill" on the left edge of the histogram, it means that there are a lot of pixels with low luminosity and the image is underexposed.

A well balanced image usually takes the full dynamic range (i.e. the histogram is stretched to limits) and the histogram is fairly symmetric.

Underexposed (dark) image	Overexposed (bright) image	Balanced (normal) image

Controls The Load settings select box lets you choose one of the predefined settings for this tab. You can also save your current settings for future use. The Contrast  moves pixels  from the center (>0) or to the center(<0) of the dynamic range. Original image Contrast (+50) applied The histogram for the original (upper) and the resulting (lower) images. The S-curve on the histogram means that the central part is stretched and the corners (highlights and shadows) are compressed. Please note that unlike contrast control behavior in other programs, no information is lost by pushing pixel values beyond the dynamic range (0-255). The Gamma "stretches" the histogram in the shadows which makes dark pixels brighter, and compresses the highlights. Or vice versa. Original image Gamma (+20) applied The histogram for the original (upper) and the resulting (lower) images The curve on the histogram shows that the left (dark) part is stretched to the right  and the highlights are compressed. Please note that no information is lost by pushing pixel values beyond the dynamic range (0-255). The Exposure makes all pixels brighter or darker by the same degree. The effect is similar to changing the ISO, exposure time or aperture on your camera. The histogram for the original (upper) and the resulting (lower) images.   The Auto contrast check box enhances the image by optimizing the dynamic range. It is done by "stretching" the histogram so that no "unused" space is left near the edges. The Black point  slider defines a color in the original image that should appear as black on the resulting image. The White point slider defines the color in the original image that should appear as white on the resulting image. These sliders define the "left" (black point) and the "right" (white point) limits for original histogram (note red lines on the image below).   Original image Autocontrast applied The histogram for the original (upper) and the resulting (lower) images. As you see, Autocontrast function "crops" the histogram: it takes only a part of the dynamic range (e.g. 20-230) and stretches it to the full dynamic range (0-255). The Local Contrast acts similarly to Auto contrast, but it is more subtle. It is very useful when there are only highlights (i.e. sky), shadows (i.e. earth) and almost without midtones. In this case you can see two big hills on the histogram . Applying local contrast will compress midtones and pull more details from the shadows and the highlights by stretching them. Original image Local contrast applied The histogram for the original (upper) and the resulting (lower) images. The Highlights  acts like Brightness or Gamma but only for light pixels. Use this control if you want to change the brightness of highlights but keep midtones and shadows unchanged. The Shadows  acts like Brightness or Gamma but only for dark pixels. Use this control if you want to change the brightness of shadows but keep midtones and highlights unchanged. Original image Shadows control applied The histogram for the original (upper) and the resulting (lower) images. On the example above the brightness of the cliff has changed but the sky stayed the same. This control does not produce halo effects. The Haze compensation can be used to minimize the haze effect. These sliders add some contrast and saturation mostly to midtones. The haze usually adds some blue color to the image and the program tries to compensate this too.  Please tune a white balance with the Color tab if you are using this function. You can also apply a similar effect locally by using the Change brightness brush with Anti-Haze effect on. Original image Resulting image The Haze/Gradient slider lets you apply a haze compensation only to a part of the image. For example,  value of +30 means that only the top 1/3 of the image will be affected. This feature is very effective for enhancing the cloudy sky. Original image Resulting image   The Exposure warnings option shows overexposed and underexposed pixels.Too bright pixels are marked with red, too dark pixels - with blue.  This option is also present with the Brightness tab. Original image Exposure warnings enabled The Brightness equalizer shows the final curve which is used by the program to modify pixel luminosity. The curve is formed by the controls above and can be additionally modified by the user. To modify the curve simply click on the equalizer or drag the curve. To reset your changes, make a right click on the equalizer. The curve can be shown as "curve" or "equalizer". You can change this option in the preferences. The "Curve" mode is an analogy of the curves in Adobe PhotoShop, it shows the function y=f(x), where x (horizontal coordinate) - luminosity of the original pixel, y (vertical coordinate)  - luminosity of the resulting pixel. If no modification is applied y = x and curve looks like a straight line. In the "Equalizer" mode the curve shows by what value the luminosity of the pixel will be changed. If the curve is a horizontal line in the middle, it means that no changes will be applied. "Equalizer" mode PS compatible "Curve" mode Brightness equalizer also shows two histograms on the background. The upper histogram shows pixel distribution of the original image, the lower - distribution of the resulting image. The Zone size slider defines if the effect of other sliders is based on the brightness of each individual pixel (slider set to 0) or it is based on some average brightness. The slider defines the size of the zone to use for such averaging. Please note, that this slider itself does not affect the image but it changes the effect of other sliders such as Gamma or Shadows. Tip: Use high values if you have only several large dark and light areas (e.g. bright sky and dark field). Use low values, if you have many small high-contrast areas (e.g. leaves on the bright sky). Set the slider to zero, if you want the changes to be applied to each pixel individually. The Autodetect slider allows the program to analyze the image and to change some controls accordingly. The slider allows you to define how strong the program may modify the image. If you apply Auto contrast the program will "stretch" the "hill" to fill the entire dynamic range and the detail level will rise. In general, you can increase the detail level by stretching the "hills" (that is to say, the concentration of pixels with similar brightness) and compressing the flat areas of the histogram. That is exactly how  Local Contrast works. Please remember that increasing the level of details also makes noise more noticeable.

Simple mode

If you prefer easy and straightforward interface, you can switch to simple mode. Go to the main menu of Helicon Filter and select "View\Simple preview mode" command. Or press button on the toolbar. 

Hints and Tips

• Try to use a full dynamic range by using Auto contrast and Exposure controls
• Use Gamma to make the histogram fairly symmetric

Recommended workflow

General workflow

• Press the reset button to set all options to defaults
• Adjust general contrast and brightness. Use Auto contrast, Gamma , Contrast and Local contrast to set optimal use of the dynamic range. In most cases the histogram should take all of the scale (i.e. dynamic range)

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Colors Tab

This tab offers you a full set of controls to adjust the colors of your image.

Please note that  some slow filters are ignored on this tab for faster preview (Noise reduction, Sharpening, Chromatic aberration, Retouching). 

To apply all filters and see a final result please switch to the Save tab. If you like the result, you can save it and process the next image. If not, you can always switch back to the filter, fine tune the settings and get an updated result.

The program remembers the settings for each file you processed. So when you open the file again, the program recalls the most recent settings for this file. You can also save the file settings manually (Menu->Settings->File Settings).

Controls The Load Settings select box lets you choose one of the predefined settings for this tab. You can also save your current settings for the future use. The R, G, B controls let you compensate for the white balance by editing red, green and blue channels respectively. Please note that a white balance compensation can also be done using the White balance button below. The Color map is an efficient tool to choose a white balance with one mouse click. You can also drag the black circle with the mouse and watch the effect at the same time.  Right click on the color map to reset it. The Saturation of the dull colors changes the intensity of dull, not saturated colors but does not effect  already saturated ones. For selective change of saturation use the Saturation equalizer. The  Saturation of the bright colors changes the intensity of the already saturated colors. Use this slider to prevent saturated areas from oversaturation. For selective change of saturation use the Saturation equalizer. The Exposure warnings option shows overexposed and underexposed pixels. Too bright pixels are marked with a red color, too dark pixels - with a blue color.  This option is also avaliable with the Brightness tab. Exposure warnings are off Exposure warnings are on The Convert to black&white option makes image monochrome and enables sliders described below to fine tune the conversion process. In this mode use RGB sliders and memory colors to define image tone (sepia, etc.). Use RGB Sensitivity sliders and an equalizer to make the image more impressive. The Load Settings select box at the top allows you to choose settings for many black and white films such as Agfa APX 100, Ilford Delta 100, etc. The Red, Green, Blue Sensitivity sliders define luminance of different colors of the spectrum. You can achieve the same effect as using special professional monochrome films by changing the sensitivity profile with these sliders and equalizer. Original image Resulting image (blue sensitivity decreased)   The Memory color  () button opens a list of predefined memory colors. You can choose sepia or other filters. Original file Black and white Sepia Blue filter The Reset button sets all controls to their default values (0). The Reset ranges ()  button removes all selected color ranges. This button is present on the tab only if you already added at least one color range. Pop up menu Pop up (or local) menu is available by left clicking on the image. When you make a left click, the program saves a color of the area beneath the mouse cursor. Let us call it the selected area. The Set white balance ()command tries to change the RGB sliders to make the selected area white/gray. To obtain better results select white, but not overexposed areas.

Memory colors

The Memory colors command opens a window with a list of predefined colors. The are called memory colors because people have a good memory for such colors as skin, foliage and water and remember other colors not very precisely.

If you select one of the memory colors by clicking on its name or its image, the program will adjust RGB sliders so that the selected area has the same color as selected memory color. If Ignore brightness checkbox is checked, the brightness of the selected area is preserved, only the tint is changed. Otherwise, the RGB sliders will be changed so that the selected area has the same color and brightness as the selected memory color. Small triangles after the color name can be used to change position of the color in the list. Delete button removes color from the list.

You can also add your own color to this list using Add this color button. For instance, you can add a natural color of your skin from your favorite photo with a good color balance. And then you can apply this color to other photos to make sure your skin has natural appearance. That means you can set a white balance by your skin when white color is not available on the image.

Color ranges

The Change color range command opens the window where you can define parameters of the selection base on color and brightness. This tool can be used to change the color of one object while keeping other colors intact.

Two squares with gradient fill correspond to the source and the target colors respectively. Memory color select lets you choose one of the predefined colors as a target color. Under the Memory color select the Color map and the Brightness map are located. The Color map in its center has a tint of the source color and a brightness of the target color. White points show the limits of the color range. Black points show a position of the target color. Click on the Color map to change a tint of the target color. The Brightness map in its center has a tint of the target color and a brightness of the source color. White points show the limits of the color range (i.e. the brightest and the darkest points). Black points show the position of the target color. Click on the Brightness map to change brightness of the target color. Zoom buttons let you change the range of colors on the Color and Brightness maps. Show selection button should be used to fine tune selection and make sure that the object is completely included into selection. Reset button makes a target color to be equal to source color. You can also define several rectangular and elliptic areas to form a selection. To create such a mask, make a left click on the image when color range dialog is open and choose "Add rectangle/ellipse to the mask" command. If Invert mask button is pressed, only pixels within defined areas will be processed.  Use Clear mask button to delete all the defined areas. Color tolerance slider defines which colors are included into selection. You can see the size of the current selection on the Color map. Press Save button to save color range and close the window. Press Cancel button to quit without saving. The List button opens another window with a list  of all color ranges. The active color ranges are marked with a white background. You can delete some of them or all at once.

When the Color range window is opened, a left click on the image will open a specific pop up menu. Use these commands to make your color range more precise and selective. Include this color into selection - adjusts selection settings (including Color tolerance slider) so that the selection also includes this color. Exclude this color from selection - adjusts selection settings (including Color tolerance slider) to exclude the color from selection. Add rectangle to the mask, Add ellipse to the mask - these commands let  you form the mask for the selection. Use the mask to protect some areas from being changed during color range transformations.

The recommended workflow to create a color range selection:

• Left click on the color on the image to be changed  and choose the Change color range command. The Color range dialog will appear. Press the Show selection button is pressed by default so you can see if the object was completely selected.
• Use Include this color into selection and  Exclude this color from selection commands only to select the target area entirely.
• If the selection includes areas you don't want to be included, use Add rectangle to the mask, Add ellipse to the mask commands to exclude undesirable areas from selection (the excluded areas will be marked with a green color)

Equalizers

To open equalizers use buttons on the colors tab.

Saturation equalizer lets you define saturation level for every hue in your image. A common task is to increase the saturation of the green tones but to keep the skin from reddening. To change the equalizer curve simply click on the equalizer or drag the curve. To reset the equalizer make a right click on it. White vertical line shows you the hue of the area beneath the mouse cursor. To set black mark on equalizer simply click on the area of interest.

Simple mode

If you prefer easy and straightforward interface, you can switch to a simple mode. Go to the main menu of Helicon Filter and select "View\Simple preview mode" command. Or press button on the toolbar. 

Hints and Tips

• Define your own memory colors (i.e. skin) and set white balance using these colors.

Recommended workflow

General workflow

• Adjust a white balance. Left click on a white/grey area and select Set white balance command. Or left click on the skin and select Memory colors command, then select appropriate skin tone.

Selective color correction

• Use the Saturation Equalizer to make green more vivid and fresh  or to desaturate reddish face. See print screen for the Saturation Equalizer as an example.
• Create the Color range selection and change the color only in the selection. See the Color ranges description for tips and hints.

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Chromatic aberration Tab

Please note that this filter is not applied on the tabs where downsized  images are used for faster preview (Brightness, Color, Distortions, Frames tabs). 

To apply all filters and see the final result please switch to the Save tab. If you like the result, you can save it and process the next image. If you don't, you can always switch back to the filter, fine tune the settings and get updated result.

The program remembers the settings for each file you processed. So when you open a file again, the program recalls the most recent settings for this file. You can also save the file settings manually (Menu->Settings->File Settings).

Chromatic aberration (CA) is a complex phenomenon caused by optical effects and processes on camera sensor.

There are two major types of chromatic aberration that appear in digital cameras: first is purple fringing and the second is lateral CA. Helicon Filter fixes both types of CA.

To get better understanding, please read the following articles:
http://www.dpreview.com/learn/?/key=chromatic+aberration

Example of purple/blue fringing (blooming):

To fix this kind of CA the program does the following.
At the first step, it defines the areas with the brightness higher than the threshold.  These overexposed areas can cause blooming effect.
At the second step, the filter desaturates the pixels which are within radius from the bright areas.
 

 Use Lateral CA slider to distort red and blue planes of the image and compensate faults of the lens. Example of lateral CA:  

The Load Settings select box lets you choose one of the predefined settings for this tab. You can also save your current settings for future use.

The Enable CA reduction check box lets you turn the filter on or off.

The Radius slider defines the distance from the overexposed areas which will be desaturated. Try to find the minimum radius, which is sufficient to remove all CA artifacts.

The Brightness threshold  slider sets minimum level of brightness for definition of overexposed areas. The filter assumes that overexposed areas (>=threshold) cause a blooming effect, normal areas (<threshold) cannot cause CA. Try to find the highest suitable threshold value to minimize artifacts in other parts of the image.

The Color tolerance  slider defines precision of the color match for chromatic aberration. The zero level of color tolerance means that only an exact color will be removed (desaturated). Very high color tolerance (100) will include all color in the processing.

The Current CA color image and The Change button let you define the exact color of the CA artifacts by clicking with the mouse pointer on the image. Based on Color tolerance level, the program will look for similar colors and desaturate them.

The Reset button turns CA filter off and sets all sliders to their default values.

The CA Map button lets you switch to special mode, where intensity of blue color corresponds to the degree of desaturation. In this mode you can check where your image is affected.

Recommended workflow

• Reset to default values and turn CA filter on.
• Find the minimum level of radius which removes the most evident CA artifacts.
• Starting from a low threshold, find the maximum threshold, sufficient for removing all CA artifacts.
• Use CA map to check if other parts of the image were not affected.

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Sharpening Tab

Sharpening is a useful feature which can make your images look much better. The basic mechanism is to find edges and make these edges more noticeable.  This effect is achieved by making brighter edge even brighter (white halo) and darker edge even darker (black halo).

Please note that the sharpening filter is not applied on the tabs where downsized  images are used for faster preview (Brightness, Color, Distortions, Frames tabs). 

To apply all filters and see the final result please switch to the Save tab. If you like the result, you can save it and process the next image. If you don't, you can always switch back to the filter, fine tune the settings and get updated result.

The program remembers the settings for each file you processed. So when you open a file again, the program recalls the most recent settings for this file. You can also save the file settings manually (Menu->Settings->File Settings).

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Controls The Load Settings select box lets you choose one of the predefined settings for this tab. You can also save your current settings for future use. Sharpen fine details - detects thin lines and fine details and amplifies them. Wider and smoother edges are not affected. Please note that such sharpening will be noticeable only on larger prints. If you plan to print 5 megapixels image on 10x15cm (4x6") paper or downsize the image to 25%, a fine sharpening will not be noticeable. Sharpen edges - increases the contrast  on the edges. Noise and fine details will not be affected.   Extreme sharpening (intensity = +100) Original image   The Edge width slider – the analog of the radius in Photoshop Unsharp mask filter. Use small values if you want to emphasize small details, use high values to stress outlines of objects. Edge width =2 Edge width =6 Edge width =10 The Threshold - sets the threshold to keep low contrast details from sharpening. Value of 100% corresponds to the detected level of noise. Original image Threshold = 0%, Intensity = 100 Threshold = 100%, Intensity = 100 Please have a closer look at the noise on the sky and low contrast details on the stones on the second and the third images. The threshold helps to prevent the sharpening of the noise. The White halo slider defines the intensity of sharpening of the white edges as a percentage of the black edge sharpening. In most cases a white halo is much more noticeable than a black halo. That is why a default value of this slider is set to 50%. Original image White halo = 50%, intensity = +50 White halo = 100%, intensity = +50 As you see, 100% white halo produces "snow" effect on the roof (image on the right).  The central image (white halo = 50%) looks more natural. The Suppress halos option makes blurred edges sharper but does not introduce white or black halos. If you already have sharp image the effect will be minimal. The Sharpening Map button lets you switch to special mode, where intensity of red color corresponds to the degree of sharpening. The green color means that these will be blurred. It is a good tool to see effects of the sharpening equalizer and the Threshold control. The original image The image after selective sharpening The sharpening map In the above example the sharpening equalizer was used to selectively smooth green background and sharpen blue object on the foreground. The sharpening map shows how different parts of the image are affected.

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The Sharpening Equalizer

To open the Sharpening equalizer use the appropriate button on the sharpening tab. Equalizer lets you define sharpening level for every hue on the image. A common task is to keep softer skin details while sharpening the rest of the image. Sample print screen on the left illustrates the above case with blue figures (see Sharpening map). Use Sharpening Map button to analyze the effects more precisely. To change the equalizer curve simply click on the equalizer or drag the curve. To reset the equalizer right click on it. White vertical line shows you the hue of the area beneath a mouse cursor. Black line shows the hue under the last click.

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Simple mode

If you prefer easy and straightforward interface, you can switch to simple mode. Go to main menu of Helicon Filter and select "View\Simple preview mode" command. Or press button on the toolbar. 

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Hints and Tips

• Do not overdo with sharpening, the image will look too "digital".
• To keep noise from being emphasized, set higher value of Threshold slider.
• To soften skin or sky use Equalizer.
• Do not set high values of Edge width without good reason, it produces halos.

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Recommended workflow

• Press reset button to set all options to defaults
• Set zoom to 100% or 50% to see image closer to real size
• Play with the Sharpen slider to sharpen outlines of objects
• If noise is emphasized, then increase value of the Threshold slider watching Sharpening Map at the same time
• Check if Suppress halos button helps to make image look better
• Use Equalizer to adjust sharpening level for specific color ranges (i.e. skin, sky)

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Distortions Tab

This tab offers you a full set of controls to compensate for radial and perspective distortions as well as vignetting.

Please note that  some slow filters are ignored on this tab for faster preview (Noise reduction, Sharpening, Chromatic aberration, Retouching). 

To apply all filters and see the final result please switch to the Save tab. If you like the result, you can save it and process the next image. If you don't, you can always switch back to the filter, fine tune the settings and get updated result.

The program remembers the settings for each file you processed. So when you open a file again, the program recalls the most recent settings for this file. You can also save the file settings manually (Menu->Settings->File Settings).

Controls The Load Settings select box lets you choose one of the predefined settings for this tab. You can also save your current settings for future use. The Enable distortions checkbox turns the whole tab on or off. The Barrel/pincushion  slider compensates radial/spherical distortions by stretching the corners. The Horizontal perspective slider squeezes left or right side of the image. The Vertical perspective slider squeezes a top or a bottom of the image. The Squeeze/stretch slider squeezes or stretches the image. The Auto crop checkbox stretches the image proportionally so that the whole image is filled. If you do not like how this function works you can define an area on the Crop&Resize tab later. The Grid checkbox adds a grid to the image to facilitate a proper alignment of the image, especially barrel and perspective distortions.  The Rotate slider lets you turn the image clockwise or counterclockwise. The Skew  slider defines the shift of the upper part of the image. The Bend slider lets you straighten the horizon by lifting/sinking  image sides relatively to the its center. The Vignetting slider defines a brightness compensation in the image's corners. The Curve steepness slider defines a brightness compensation degree along the radius.  High values result in correction only in the corners, low values let you also correct other parts of the image. The Compare mode checkbox emphasizes the vignetting effect by adding mirror images from each side of the image. You can find the optimal parameters in this mode easier. Original image, usual mode Original image, compare mode

Simple mode

If you prefer an easy and straightforward interface, you can switch to simple mode. Go to main menu of Helicon Filter and select "View\Simple preview mode" command. Or press button on the toolbar. 

Hints and Tips

• The less you change the image, the better
• Switch on the Grid for distortion correction.
• Switch on the Compare mode for vignetting correction.

Recommended workflow

General workflow

• Switch on the Grid and check if the image has distortions.  Correct distortions if needed.
• Switch on the Compare mode to check if the image has vignetting. Correct vignetting if needed.

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Resize Tab

This tab has a full set of tools to prepare the final image for printing or publishing on the web. You can crop, rotate and resize the image to the target size.

Please note that  some slow filters are ignored on this tab for faster preview (Noise reduction, Sharpening, Chromatic aberration, Retouching). 

To apply all filters and see a final result please switch to the Save tab. If you like the result, you can save it and process the next image. If you don't, you can always switch back to the filter, fine tune the settings and get an updated result.

The program remembers the settings for each file you processed. So when you open the file again, the program recalls the most recent settings for this file. You can also save the file settings manually (Menu->Settings->File Settings).

The Load Settings select box lets you choose one of the predefined settings for this tab. You can also save your current settings for the future use.

The Enable Cropping check box lets you turn the whole tab on or off.

The Landscape ()/Portrait () switch lets you rotate selection by 90 degrees keeping the aspect ratio intact.

The Paper radio button shows the list of the Load Settings for printing on paper.
The New size  list lets you define the resulting size and the proportions (aspect ratio) of the selection. If "no resize" option is chosen, then the aspect ratio is set to 2:3.
Please note, that the program uses the standard value of 300 dpi (dots per inch) to obtain a final resolution of the image in pixels.

The Web radio button shows the list of the Load Settings for publishing on the web.
The New size  list lets you choose the resulting size and the proportions (aspect ratio) of the selection.

If the Crop only option is chosen the program just crops the image and it does not resize it to some target size.

The Mobile radio button shows the list of the Load Settings for mobile devices grouped by the leading producers.

The User defined radio button shows additional fields to set directly resulting width and height in inches, centimeters, pixels or percents. 

If the  Keep aspect ratio checkbox is checked, the program automatically updates the size of other size of the image to keep proportions of the selection .

The  Limit longer size checkbox is very useful if you would like to resize images in a batch mode. The images may have different aspect ratio and orientation. But still you can specify a maximum size to fit in. Aspect ratio of the original image is always preserved in this mode.

The New size  check box lets you apply user-defined size and fix the proportions (aspect ratio) of the selection. If  the check box is off, the aspect ration of the selection is not fixed and no resize would be performed.

The Reset  button sets almost all controls to default values but preserves orientation of the selection (portrait/landscape) and target type (paper/web/user defined).

The Real size  button shows the image in a full screen mode with the size the image would have on the target device (paper, monitor). For example, if you choose resize to 4x6" (10x15cm), the image on your screen will be of approximately of the same size.

You can rotate the selection using a mouse wheel , a right mouse button or the buttons and . You can reset rotation with button.

The Reset selection  button tries to stretch selection to fit the image. The double click by the mouse has the same effect has.

Recommended workflow

• Choose the target type (paper/web/user defined).
• Choose orientation of selection (portrait/landscape).
• Change selection size by dragging the frame.
• Move selection by dragging the image within the frame.
• Rotate selection by dragging the image outside the frame or by using a mouse wheel.

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Frame Tab -  Overview

This tab lets you add to the image a text of your own, current date, time or additional info from EXIF information .

Please note that  some slow filters are ignored on this tab for faster preview (Noise reduction, Sharpening, Chromatic aberration, Retouching). 

To apply all filters and see the final result please switch to the Save tab. If you like the result, you can save it and process the next image. If you don't, you can always switch back to the filter, fine tune the settings and get updated result.

The program remembers the settings for each file you processed. So when you open a file again, the program recalls the most recent settings for this file. You can also save the file settings manually (Menu->Settings->File Settings).

Simple mode

In the Simple mode some buttons will are hidden.  To select Simple mode, go to the main menu of Helicon Filter and select "View\Simple preview mode" command. Or press button on the toolbar. 

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Retouching tab

This tab offers full set of brushes to fix artifacts on the image manually.

Shortcuts:

Use Right mouse button to switch to the source image and to drag the image.

Use Mouse wheel to change brush size.

+ Use Shift+Mouse wheel to change an active slider. For example, you can click Intensity slider and then change it with the mouse.

+ Use Shift+Left click to draw line between two points.

Common parameters:

Brush size slider defines the size of a brush in pixels.

Brush hardness  slider defines the form of a brush edge.

Intensity slider defines the strength of a brush effect.

Edge sensitivity  slider makes the brush smarter: the mouse pointer is changed to double circle (), the effect to external circle is applied only if the color is similar to those in the internal circle. On the following image  the left point was made with this option, the right one without edge detection.

The Fill contour button () lets you fill the outlined area with the same brush. You can use this command to apply all brushes except Delete scratches and Distort brush.

The Undo/Redo slider and the buttons let you easily undo and redo your actions on this tab. The number on the slider indicates the quantity of points. The percentage in brackets shows the share of the points that are currently visible on the screen. If you set the slider to 0%, it means that all your actions are canceled.

Undo button cancels the last stroke. A stroke is a set of points in one continuous line.  Redo button brings back the next point.  So you are able to make a big step backwards (cancel the whole line) and then proceed point by point.

or  +Z.  The keyboard shortcuts for Undo are Left arrow and Ctlr-Z

or  +Y.  The keyboard shortcuts for Redo are Right arrow and Ctlr-Y

The Reset button undoes all the operations on the Retouching tab. But you can apply all of them again by moving the undo/redo slider to 100%.

Clone brush A clone brush lets you copy a part of the image from "source" to "target" area.  After you have chosen the clone brush, you will see the mouse pointer as a green cross in a green circle (). Simply click the image to select the source area. Once you've selected the source area, the mouse pointer changes to its usual circle form () to select the target area and apply the brush. If Do not move source option is checked, the source area does not move together with a mouse pointer. The target is filled with the pattern from the source area. If the above option is not checked (default state), the source area moves parallel to the mouse pointer.

or +   Use Right click or Ctrl+Left click  to set a new source area.

The intensity slider defines the opacity of the area to copy.

Delete scratches brush This is a smart brush which automatically fills the area under the brush with neighboring pixels. This brush is optimized to fix small artifacts such as wrinkles, scratches, pimples, etc.

Original image The brush ready to apply Resulting image

Normally the brush changes its orientation according to the mouse movements. Such mode is sufficient for areas with fine or no texture.

If the scratch is crossing some edges, lines or coarse texture, it is better to use a manual orientation so that the brush is perpendicular to the lines it is crossing.

  + or  Use Ctrl+Mouse wheel or Up/Down keys  to change orientation of the brush.
Keep Ctrl key pressed to fix orientation of the brush

The area between short lines and a circle is used to fill the area inside of a brush circle.  For example, you can also easily "erase" wires on the image below by dragging the brush.

Using autooriented brush	Using manually oriented brush to minimize artifacts

The brush clones the texture from its sides, so the texture is preserved.

Original image	Resulting image after only one click

Change brightness brush This brush is designed to brighten or darken selected areas. If the Intensity slider has a positive level, the brush increases a brightness of pixels. If the intensity is negative, the brightness decreases. If the Remove haze option is set, the brush decreases the brightness, adds some saturation and compensates bluish effect produced by a haze. Please note, that you can apply also Haze Compensation slider to the whole image on the Brightnesss tab. Original image Resulting image

Change color brush You can use this brush to paint with the selected color or to change a hue keeping the brightness and saturation intact. You can select a brush color in tree ways: The Color picker button () lets you select a color from the current image simply by clicking an appropriate area. The selected color will then be shown in the rectangle under the sliders. The Color dialog button () opens a standard dialog to choose a color from the palette.  The Memory colors list () contains some predefined colors such as skin or sky colors and lets you add your own colors to this list. If the Keep the brightness option is checked the brush changes  the tint (hue). The Intensity sliders changes to Saturation slider. It lets you change the saturation of the applied color. To keep an original saturation, set slider to 0.

Original image Resulting image

TIP: This brush enables you to fix a reddish skin  very easily.  Select natural skin color from the same person with Color picker, then turn on Keep the brightness option and paint with the brush over a reddish face.  Fine tune the Saturation slider is to get a natural look.

Selecting natural skin color from original image	Applying the brush

Change saturation brush This brush increases or decreases a saturation of affected pixels. If the Intensity is positive, the colors become more vivid. Use Intensity of -100% to make the selection monochrome (grayscale).

Original image The internal part is saturated The internal part is desaturated

Blur/Sharpen brush The blur brush (negative intensity) can be used to smooth noise or artifacts in the selected areas. You can also blur background to emphasize the foreground (often in portrait photos). The sharpen brush (positive intensity) can be used to selectively sharpen some areas (e.g. trees) but keep other areas (e.g. skin, sky ) intact. On the example below the background was slightly blurred and the foreground sharpened to emphasize the depth of field.

Original image Partially blurred and sharpened

Reduce noise brush This brush uses Aggressive algorithm to reduce noise only in the given areas. A default value of the Intensity slider is set to detected noise level in the same way as it is done on the Noise tab. Higher values of the Intensity slider mean that more details will be considered noise and removed.

Original image  Noise selectively removed

Fix red eye brush This brush desaturates a pupil of the eye and makes it darker. The brush tries to define edges of the pupil so it can be used when the pupil is not round. The Pupil darkening slider defines  brightness of the desaturated pupil. The value of 50 means that the brightness is reduced by 50%.

Distort brush This brush lets you locally distort the image. You can fix such problems as face expression, thin lips, protruding ears, etc. The Both directions checkbox lets you stretch or squeeze the image area symmetrically relatively to a brush center. Use this option to make  prolonged objects  like lips or legs thicker of thinner. One directional distortion Squeezing in both directions Stretching in both directions

Before After

+ or  Use Ctrl+Mouse wheel or Up/Down keys  to change orientation of the brush.
Keep Ctrl key pressed to fix orientation of the brush

Replace sky brush This brush lets you clone the sky from external image. The primary goal of the brush is to replace an overexposed sky with more appropriate one. Please do not forget that using completely different sky type will make the image look unnatural due to differences in lightening, shadow directions, etc. Please note that Intensity slider changes the opacity of the whole sky image. If you want to make only a part of the sky semi-transparent, please use Erase changes brush later on. Tip: when painting near the horizon, set  Edge sensitivity to maximum value and paint with single clicks. The Open sky library button opens a folder with the sky images supplied with the program. You can copy your own image to this folder. The Open user's sky  button opens previously used folder to load user's image with the sky. The Horizon level  slider lets you squeeze the sky image so that the final image looks more natural.

Erase changes brush

This brush is designed to erase selectively the effect of the previous brushes.  You can restore the pixels to the state they were before retouching or even to the their original state.

If the Restore to original  option is checked then the program will restore the pixels from the very original image as it was loaded from the disk. If the option is not checked, the program will restore pixels to the state before retouching. This option makes a difference only if you have applied some filters (brightness, colors, etc.) before calling the retouching filter.

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Save tab

Switching to Save tab makes the program apply all the filters to the source image and show a final result. From the Save tab you can switch back to filters to adjust settings and apply them anew.

On the top of this tab you can select the next action which you want to be performed with the result image. Please see the detailed description of each action below.

  Save to disk action

The File name edit box contains a name of the file to be saved on the disk. By default the result name is formed by source image name and suffix (HF) to not accidentally overwrite the original image.

The File type select box lets you choose among JPEG, TIFF and other file types.

The Quality  select defines the quality level for JPEG and JPEG2000 file types ("lossy" formats).  Please note, that TIFF, BMP provide lossless storage of the information. If you plan further processing of the image, it is recommended to store it in lossless format (TIFF) or at least in 100% JPEG. If you plan to print the image, 10 (80%) quality is usually sufficient.

The Calculate size  button shows the size of the file for the selected file type and quality level. If the file is too large, try to lower JPEG quality. If this does not help, switch to Resize filter and downsize the image to lower resolution. If you plan to email this image, it is recommended to keep the file size at 50-200KB and downsize it to 800-1280 pixels on greater side.

You can define the target folder where the image should be saved:

Select   source folder  option to save the file near the source image, in the same folder.

Select   subfolder in the source folder option and define subfolder name to save the filtered image in the subfolder. You can use this option if you do not like to change the name of the original image.

Select defined user folder option and select a folder with the open button where the file should be saved.

Send by email action

Choose this action to send the result image by email. The program will try to use your default mail client to send this email.

The Change image size select box lets you change a resolution of the image to reduce its size. To check new file size use "Calculate file size" button.

Print action

Print dialog lets you prepare the image for printing.

The Printer select box contains all printers available in the system.
 

The Original image option calculates the image size in mm based on 300 DPI resolution. This means, that 300x300 image will have size of 1 X 1 inch or 25.4x25.4mm.
The Fit to page option adjusts the image size so that it takes all the paper width.
The Custom option lets you insert absolute values for image size.

The Units select box lets you choose from inches, centimeters and percents you inserted as absolute values for image size.

Send to mobile phone action

This dialog lets you send the image together with your comments to almost any mobile phone in the world.
The image is uploaded to our server and then the link to the page with the image and your comments is sent as SMS.

Helicon Filter uses global SMS provider to deliver messages to almost all countries in the world.
Please note that registered users automatically receive some number of messages to their account in our online system.
Unregistered users can also use this feature but only if a daily limit for free SMS messages is not yet exceeded. 

The From (name) edit box should normally contain your name. This name is used in SMS text to let the recipient know who sends the message.   Many people ignore SMS from unknown source.

The To (name)  edit box is used to save the phone number in the address book.

The Phone number edit box should contain a valid phone number under international format. The number should start with the phone code of your country. Please do not put "+" or "00" at the beginning of the phone number.

The Address book select box contains all phone numbers and names to whom you have sent messages.

The Message text edit area lets you enter the text which will be sent  together with the image.

The Make public  check box defines if you want that your image is publicly available at our site. When setting this option, please make sure you understand the conditions shown in the message right after that.

The Category  select  box lets you choose the category of the gallery where your image will be published.

The Size  options define a resolution of the image in pixels. Please note that most users do not want to receive big (over 20Kb) images. To minimize a file size, EXIF and IPTC information is preserved only if the maximum size is chosen.

On your click on Send  button, the program tries to upload image to our server and normally returns you a link that was sent to your addressee. You can open this link in the browser to check if everything is ok. You can also send this link via email or instant messengers to your friends.

 Apply to folder action

If you are satisfied with the resulting image, you can apply the same setting and process all files in the current folder.

After you press the Apply button you will see the Queue dialog, where you can check the list of files and start processing.

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Batch processing

The Home and Pro versions  offer you a powerful feature of processing many images in automatic mode. The noise reduction algorithm automatically detects the noise level so it is not necessary to set the options for each image. Even if you want to set options for each image separately there is no need to wait for the image to be processed. You can queue this job and perform it later.

Adding an image to the queue

To add the image to the queue use hotkey F6 or the menu command Queue\Add and load next. To change the settings of the image that is already in the queue simply add it to queue again. If you want that current options to be applied to all images in the folder, use the menu command Queue\Add all to queue. You can also add one or several images to the Queue from the navigation panel using context menu.

Editing queue and starting batch processing

You can check which images were added to the queue. Press F7 or call the menu command Queue\Show Queue... to see the list of images to be processed.

In the Queue dialog you can remove one or all images, edit options for each images and start batch processing by Start button.

Setting batch options

Please, before starting the batch processing check the parameters on the Options tab in the Queue dialog.

Here you can select the output file format, the output directory and the output name.

By default the output images are saved in the subdirectory of source directory with the name "filtered".

The output name is created from a source name by adding prefix and/or suffix. Default suffix is "_hnf".

Starting the batch processing

Press the Start button in the Queue dialog.

You will see a progress bar for the current image and for the whole queue.
You will also see a preview of the current image. In the report window, the list of processed images is shown with the level of detected noise. If this level seems to be abnormally low or high, check this image manually.

The processed images are removed from the queue. You can stop processing and close the program. The queue contents will be saved and you will be able to continue processing later.

Calling Helicon Filter from Adobe Photoshop

After installation of the program, Helicon Filter plug-in will be automatically added to the most popular programs that support PS-compatible plug-ins.

Helicon Filter automatically registers itself in the following software packages:

• Adobe Photoshop 6.0+
• Adobe Photoshop Elements 2.0+
• Corel Photo-Paint
• Jacs Paint-Shop Pro 8.0+

If you have program that support PS-compatible plug-ins but are not included in this list, please let us know. We will include them in the next version.

To register a plug-in manually, copy file "c:\program files\Helicon Software\Helicon Filter\library\HeliconFilter.8bf" to the folder with plug-ins.

Helicon Filter Plug-in can handle 16-bit per channel images and images with embedded color profile.

Helicon Filter Plug-in is available in the Pro version and is not available in the Home version.  During a 30 days evaluation period it is available in all versions.

Calling PS-compatible plug-ins  from Helicon Filter

Helicon Filter can be used to call installed PS-compatible plug-ins.

Helicon Filter looks for installed plug-ins in the folders of popular software packages like Adobe Photoshop or Corel Photo-Paint. All compatible plug-ins are added to the Plugins menu of the Helicon Filter.

To add external plug-ins manually, please copy plug-in file to the appropriate folder of Helicon Filter ("c:\program files\Helicon Software\Helicon Filter\Plug-ins\")

If you are working with raw or tiff images and external plug-in does not support 16-bit per channel images, then the image will be converted to 8 bit and then again to 16 bit after plug-in call. This may cause some loss of details. In this case, use such plug-in at the last step.

Thanks to generous permission of Harald Heim, we included Harry's Filters 3.0 to our installation. You can get the latest version of this package on www.ThePluginSite.com.
 

If you have problems calling plug-ins from Helicon Filter, please let us know.

The Dynamic Range

The dynamic range is a ratio of the brightest and the darkest spot of the image.

Usual 8 bit images are limited to 256:1 dynamic range, which is a standard for the majority of monitors and printing devices. Only professional monitors support 10 bit quality (1024:1).

Raw files use 10, 12 or 14 bits for each channel (R,G,B), and it allows to increase theoretical dynamic range to 1024:1, 4096:1 to 16364:1 accordingly. But in fact the lowest bits in RAW files contain mostly noise, so the actual dynamic range of a digital camera is limited to 8-10 bits (256-1024:1).

The dynamic range of live scenes is often much higher. For example, a usual scene on a sunny day has a dynamic range of about 100 000:1. No digital camera can capture such scene without losses (underexposed shadows and overexposed sky).

The Helicon Filter has a special tool  to combine information from several shots of the same scene into one image with the high dynamic range. The resulting image is stored in 16 bit quality (65536:1) which allows you to extract hidden information without quality loss.

The program aligns the images, takes the highlights from the underexposed image,  shadows from overexposed image and combines them into one image with the high dynamic range.

Please note that only higher 8 bits can be shown on standard output devices. To "optimize" the dynamic range you can use the controls on the Brightness tab : Gamma, Shadows, Highlights, the Curve/Equalizer.

Underexposed, image is too dark, details in the shadows are lost	Overexposed, image is too bright, details in the highlights are lost	Combined with high dynamic range

Making shots

• Switch your camera to manual exposure mode (usually marked as AVM or M).
• Set aperture and exposure time to shot details in the shadows.
• Decrease exposure time until the highlights are properly exposed.  Do not change aperture as it changes a field depth and may result in visual artifacts.

• Switch your camera to the exposure bracketing mode.
• Set maximum bracketing values available on your camera (5 shots, 1 EV step)
• Make shots

Using manual mode will allow you to get a higher dynamic range but it requires the use of a tripod. The bracketing mode will give you only a limited number (2-4) of additional f-stops but it does not require a tripod.

Merging images to increase dynamic range

• Open the darkest image from the sequence with the Helicon Filter.
• Choose "menu->Edit->Increase dynamic range ... " command, press OK
• Choose the brighter image and merge it. Add all following images in the same way
• Go to the brightness tab and increase the Gamma to make the details in the shadows brighter.
• Use the Shadows and the Highlights controls to fine tune the image.

Hints and Tips

• The order in which you combine the image has no particular importance.  In the normal case the result should be the same.
• If the program is not able to align the images correctly, try to change the order.

To show or  hide Help panel of Helicon Filter use button from the toolbar or View->Help panel command in the main menu.

Preferences window

To open the Preference window use the menu command Settings\Preferences.

General tab:

Accelerator for dragging the image - makes navigation in the main window more efficient by moving the image faster than by a mouse. Brightness management - choose between "curve" and "equalizer" mode of the brightness equalizer. Ignoring the EXIF information option can be useful if you do not want to include EXIF in the output image. Help Hints appearance select lets you define behavior of the tooltips. When you place a mouse cursor over a slider or a button, additional information about it will be displayed as a tooltip or in the status bar, in both places or nowhere at all. Enable noise reduction by default option defines if the noise reduction tab is enabled or disabled when user resets all options. Reset settings for new image option defines if the settings stay intact or are reset to default when the user loads  the next image. Restore the last file settings option defines if the settings that were used for previous editing should be loaded. Check for updates checkbox defines if the program should check availability of newer versions. This may cause problems under some network configurations. Automatically rotate image when opening checkbox tells the program to use EXIF information about the image's orientation. Open last edited image on program start checkbox controls if a recently edited image should be automatically opened. Allow to use external plugins checkbox defines if the program should search for compatible Photoshop-compatible plugins and show them in the menu. Use the following color profile when saving images checkbox tells the program which color space to use. Please note, that many programs do not correctly display images in color spaces other than sRGB. So it may be a good idea to convert to sRGB before sending image to other people. But converting from Adobe RGB to sRGB  may result in some color clipping.

Cache tab:

Enable cache for thumbnails  option defines if the program saves the thumbnails onto a disk for future use. Each thumbnail takes only some 10-15 Kb (less then 1% of the image size) but the cache significantly increases the speed of the navigation panel . Enable cache for settings of processed images  option defines if the program should restore the settings that were used earlier to process this image. This can be very useful if you are not satisfied with the result and want to change only some parameters leaving the others as they were set during the first processing.

RAW tab:

The Raw format select contains all RAW formats supported by the program. You can set parameters for each RAW format individually. Please select the RAW format to see which parameters are available. Parameters for RAW development without manufacturer's SDK: The Demosaic method select lets you choose between linear, medium quality (VNG) and highest quality (AHD) methods of interpolation. AHD will sometimes result in fewer color artifacts around sharp image edges, but it can be applied only to some RAW formats. To get more information about VNG and AHD methods, please read http://www.aim-dtp.net/aim/digicam/dcraw/vng-ahd-comparison.htm The Adjust contrast  checkbox  tells the program to clip shadows and highlights to increase overall image contrast. Some minor details in shadows and highlights may be lost. The Use camera white balance  checkbox lets the program use information about white balance which is available in the RAW file. Otherwise no color correction is performed. The Use CIECAM02  checkbox controls a type of color algorithms used during digital camera raw processing. CIECAM02 is a color appearance model that describes the transformations between colorspaces where the overall characteristics of the scene are taken into account.  If not checked a more precise method is used that offers less scene characteristic adjustment than CIECAM02 does, but frequently provides better image characteristics in dimly lit portions of a high dynamic range image. The Set white balance as on the thumbnail checkbox makes the program use a thumbnail as a source of white balance and contrast information.  Camera manufacturers often hide and encrypt white balance information. Thumbnail is generated by a camera and often it is more adequate than the converted raw file. Please note that this operation is performed on the final stage of RAW development so all previous options may be completely overridden. Canon RAW parameters: The Use camera defaults  checkbox defines if the Canon SDK’s default processing will be used and other options  will be ignored. The Contrast select controls the image contrast. The Color depth select controls the image color depth. The Enhancement select controls the performed enhancement of the image. The Light source select controls the lighting source assumption made during image processing. Kodak RAW parameters: The Light source select controls the lighting source assumption made during image processing. The Exposure bias select defines the exposure gain to use for the image being opened. You  may try to use negative values to save overexposed highlights. The Color reproduction select controls a color accuracy during the development process. The Final processing select defines a saturation of the image. Portrait mode produces less saturated look when capturing images of people. Nikon RAW parameters: The Use Nikon SDK checkbox defines if Nikon libraries should be used to open a RAW file.

Audio/Video tab:

Play sound for events  option lets you choose if you want to hear beep after long operations.  Play voice comments automatically checkbox defines if the associated sound is played when image is opened. Sound volume slider defines the volume for voice comments. Audio device select lets you choose from available sound cards and other audio devices. Audio source select lets you choose the input line of your sound card. Quality select offers you a list of available codecs. Higher bit rates usually correspond to higher quality and file size.

Shortcuts reference

This page contains  combinations of keys (shortcuts or hotkeys) that can be used for direct call of certain commands.

Please consider printing out this page to have it close at hand.

Basic shortcuts

Right mouse button	Click on the image: to compare with the original image or drag the image (pan) Click on a slider or equalizer: to reset to default value
Left mouse button	Retouching: to apply the selected brush Images on other windows:to call context menu
Mouse wheel	Change a zoom factor
+ Shift+Mouse wheel	Change an active slider (a green one)

Retouching only

Mouse wheel	All brushes: to change brush size
+ Shift+Left button	All brushes: to draw the line between two points (previous and current ones).
Left arrow  or  Ctrl+Z.	Undo
Right arrow or  Ctrl+Y	Redo
Right mouse button or + Ctrl+Left mouse button	Clone brush only: to set a new source area
+ Ctrl+Mouse wheel or  Up/Down keys	Distort and Delete scratches brushes: to change orientation of the brush
Ctrl key	Distort and Delete scratches brushes:to fix orientation of the brush
A,Z keys	All brushes: to change a value of the Intensity slider

Other commands

Updates and support

We support users via email (filter@helicon.com.ua) and in the forum (http://www.helicon.com.ua/forum/). Naturally, registered users are served first.

Contacts

Web:

• http://www.heliconfilter.com
• http://www.heliconsoft.com/

Emails:

• filter@helicon.com.ua
• DanKozub@helicon.com.ua

Post address:
Helicon Soft Ltd.
per. Mekhanichesky 4
61068 Kharkov
Ukraine

Phones:
Tel: +380-67-579-52-44
Fax: +380-57-738-20-17

Copyright

Authors: Danylo Kozub, Vitaly Khmelik, Juri Shapoval, Vitaly Chentsov, Stas Yatsenko

Helicon Soft Ltd. (c) 2000 - 2008
All rights reserved.

Tutorials

What is the recommended workflow

How to fix a reddish face

How to reduce noise selectively

How to set a white balance

How to use the histogram

What is the recommended workflow

Suppose you shot an image and you have it on the disk. Helicon Filter has many controls, so many users ask what they should start from.

Helicon Filter was designed to follow widely accepted post processing workflow: "Noise Reduction >> Brightness, Colors adjustment >> other filters >> Sharpening"

The important point is that noise should be removed before making all other changes, sharpening usually is done at the end, while sharpening introduces much more artifacts than any other filter.

The unique feature of Helicon Filter is that you can switch between filters back and forth, you can change settings many times to get the best result. Each time your settings will be applied to 16 bit copy of the original image, so you will not loose quality due to multiple use of the same filter or due to operations on 8 bit images.

A general rule for the workflow is to open each tab from the left to the right and activate the filters you need.

As an example we will use the following image kindly provided by Derek Drury:

Step 1. Open the source image

You can open an image with the usual Open Dialog (menu->File->Open) or you can choose the image from the file browser on the Source tab.

If you would like to experiment with the sample image, I would suggest you coping the image from this page and paste it into Helicon Filter.

Step 2. Reduce noise

Once you've opened the image, switch to the Noise tab. Set 100% magnification and decide if the noise is too strong. Check the Enable noise reduction box if needed. Do not try to fine tune noise reduction now - first set up other filters (brightness, sharpening) and then return to the Noise tab to find the best settings.

Original image	After default noise reduction

Step 3. Normalize the brightness

The brightness settings affect the image the most. In many cases I start from this filter and fine tune the others only afterwards.

Your main task now is to optimize the brightness so that the image takes the whole dynamic range.  This will make your image bright, colorful and and full of details.

Please read the tutorial How to use the histogram to learn more about this process.

To be short: use Auto contrast and Haze compensation first. Then use other controls to fine tune the image.

Original image	After Brightness filter

For this particular image I've used the Auto contrast sliders first, then the Shadows slider.

Step 4.  Set the white balance

Now switch to the Colors tab. You can change the tone of the image here using the Colors map or point-and-click White balance tools.

Please read the tutorial How to set white balance to learn more about this process.

After Brightness filter	After Colors filter

Step 5.  Apply sharpening

Now switch to the Sharpening tab.

Helicon Filter offers many controls to get the best result.

In short:

- use Sharpen fine details to make good image even crisper
- use Sharpen edges to emphasize the edges of the objects on the soft images
- use Threshold to keep excessive noise from sharpening
- use Suppress halos or White halo if halos are too noticeable

Please be cautious, you can easily spoil a good image applying too much sharpening on it.

Before sharpening	After Sharpening

For this image I've turned on the Suppress halos feature to get rid of strong halos around the bright dots on the dress.

Step 6.  Retouch the image

Now switch to the Retouching tab.

Helicon Filter has full set of retouching brushes. For this image I will use the  Clone brush to erase black shadow in the right corner of the image.

Before Retouching	After Retouching

Step 7.  Save the resulting image.

Switch to the Save tab. You can preview your result now and compare it with the original using the right mouse button.

Original image	Resulting image

If you are contented with your result, switch to Save tab and save the result as usual.

If you are not, feel free to return to the filters, change your settings and process the original image with new settings.
To restart from a scratch, reset all settings with button.

If you have suggestions for changes to Helicon Filter or to the help and tutorials, please contact us at filter@helicon.com.ua

Helicon Soft Ltd. © 2000-2008

How to fix a reddish face

In this tutorial we will discuss how you can fix a reddish face with Helicon Filter in several minutes. We will use the following image as example (download original, 5Mp, 2.5M):

As you can see, this shot cannot be fixed by changing the saturation of the whole image. In this case other parts of the image will be unnaturally pale.

So the best way is to use Retouching brushes to make local changes on the man's face.

Step 1. Open a source image

You can open an image with the usual Open Dialog (menu->File->Open) or you can choose the image from the file browser on the Source tab.

If you would like to experiment with this sample image, I would suggest you to copy the image from this page and paste it into Helicon Filter.

Step 2. Switch to the Retouching tab.

Once you've opened the image, switch to the Retouching tab and select the Change color brush.

Set the brush parameters to the appropriate values.

Preserve brightness: Ensure this is ticked to turn it on. We want to change the tint of the skin but preserve the texture and details. Saturation slider: set it to 0%. This means that the original saturation level will not be changed. If needed he level can be changed later. Brush size: Let's try a value of 13. Brush hardness: Set it to 80%. Too hard edges will make your changes too noticeable. Too soft edge will not allow to you change the face edges. Edge sensitivity: Leave it at 0%. In this case it is quite easy to select the whole face with a regular brush without edge sensitivity. Sensitive brush works best on contrast edges with many small details like tree outline.

Step 3. Select natural skin color

The simplest way is to select natural color from the same image using  the Color Picker ( ):

If there are no such color on the image, you can select skin color from the Memory Colors ():

Please note, that you can add your own items  to the Memory Colors right here (Pick some color, then open Memory colors, then  "Add this color").

You can also add a Memory color from the Colors tab.

Step 4.  Try the brush and fine tuning of settings.

It is time to apply the brush and see if the result is good enough. As it is a draft, there is no need to be cautious with edges:

Original image	The first result

Well, as it is a trial, the man's face looks a bit yellow. The main reason for this was leaving the saturation level of the original area unchanged (0%).

Let us change Saturation slider to -18%, now reset all changes and try again:

Original image	The draft result

Now the face looks quite natural but you can get better results by changing a color and saturation values. I would suggest to select other skin color from the Memory colors and try again.

Step 5.  Fine tuning of the result.

As I was not careful enought painting over the face, I've also changed the color of the lips, eyes and a part of the wall  under a left ear.

Now, let us switch to the Erase changes brush to revert these areas to their original color:

Draft image with artifacts	The final result

Step 6.  Save the resulting image.

If you are contented with your result, switch to Save tab and save the result as usual.

If you open the original image later the program will "recall" all parameters that were applied last time. Consequently you will be able to continue editing the original image.

If you have any suggestions for changes to Helicon Filter or to the help and tutorials, please contact us at filter@helicon.com.ua

Helicon Soft Ltd. © 2000-2008

How to reduce noise selectively

Selective noise reduction is a very powerful feature of Helicon Filter. You can clean noise in some areas and keep details in other areas using such tools as Noise Equalizer, Color Ranges and Reduce noise brush.

As an example we will use a crop from the image that was made with ISO 100 and exposure of 1/320 s (download original image here). 

Even with low ISO and short exposure the image demonstrates a quite noticeable noise on the sky. 

It gets even worse after we apply some auto contrast and sharpening:

The image above will be our starting point for noise reduction.

Step 1. Open the source image

You can download  original image (4Mp, 851K), open it with the usual Open Dialog (menu->File->Open) and apply Auto contrast and Sharpening (threshold=0).

If you would like to experiment with this sample crop, I would suggest you to copy the image from this page and paste it into Helicon Filter with Ctrl-V shortcut.

Step 2. Switch to the Noise tab and apply default settings

Once you've opened the image, switch to the Noise tab and set Enable noise reduction check box.

Default noise reduction is applied to the image and now the result looks like this:

As you can see, the noise on the sky is almost deleted completely . But the texture of the mountains and trees were also affected.

Step 3. Turn on a noise map

It is hight time now to use advanced tools of noise reduction.

Please enable double window mode from the toolbar () of menu (menu->View->Frames->Double).

And enable the noise map by pressing on the appropriate button on the right.

The red color on the noise reduction map shows us that the program will apply noise reduction to all parts of the image. We will try to make the reduction more selective.

Step 4.  Use noise equalizer for selective noise reduction

As we would like to clean noise only on the sky, we need to tell the program to process only blue areas and ignore others.

To make this, please turn on the Equalizer  and "draw" the following curve:

The curve tells the program to use high (+100%) noise reduction in the blue areas and use low (-100%) noise reduction in all other areas.

Now let's look at the noise map:

The results are much better now. Red color marks the areas where noise should be reduced. We can see only small red spots on the mountain.

Now turn off a noise map, switch to the Save tab to check if you are satisfied with the final image.

For simple cases like this, Equalizer and  the Noise map are quick and efficient tools for selective noise reduction. If you would like to get to know about other tools, keep reading this tutorial.

Step 5.  Use color ranges for selective noise reduction

Sometimes you need to clean light-blue areas and keep dark-blue areas intact. In such case you cannot use Equalizer as it does not differentiate between dark and light colors. Still Helicon Filter provides you with a necessary tool which is called Color Ranges .

With Color ranges tool you can adjust noise reduction level for each color tint.

To see the effect of Color ranges tool please enable Noise map.

Now, click on the blue sky with the left mouse button. You will see a small popup menu:

Increase noise reduction for the sky and repeat this operation several times. Each command increases the noise reduction level by 50%.

Now, click on the mountain where the details should be preserved. Repeat "Decrease noise reduction" command until the noise map will look like this:

Step 6.  Save the resulting image.

If you are contented with your result, switch to Save tab and save the result onto a disk.

	Original image with  Auto  contrast and  Sharpening applied
	The image after selective noise reduction. No noise on the sky, details and textures on the mountain preserved.

If you open the original image later the program will "recall" all parameters that were applied last time. So you will be able to continue editing the original image.

If you have any suggestions for changes to Helicon Filter or to the help and tutorials, please contact us at filter@helicon.com.ua

Helicon Soft Ltd. © 2000-2008

How to set white balance

The "color" of the light is always different. The suns rays passing through the atmosphere change their spectrum. The spectrum of artificial illumination is never absolutely white.

The human brain adapts to the color casts instinctively so we usually do not notice the changes of the "white balance" of natural scenes.

The digital camera also tries to compensate color casts, but cannot do this as smart as the human brain does. In many cases the color cast (white balance) will have to be fixed in post processing.

As an example we will use the following image kindly provided by Derek Drury:

The image has a slight red color cast and we will try to fix it with Helicon Filter.

Step 1. Open the source image

You can open an image with the usual Open Dialog (menu->File->Open) or you can choose an image from the file browser with the Source tab.

If you would like to experiment with this sample image, I would suggest you to copy the image from this page and paste it into Helicon Filter.

Step 2. Correct white balance with the Color map.

Once you've opened the image, switch to the Colors tab. Now drag the black circle and watch how the image is changing.

Once you've found the best state you release the mouse button. You can Save the image now if you are contented with the result.

The problem with this fast and easy method is in making the right choice. Indeed you should have a very good eye and feeling to set the white balance manually.

Step 3. Set white balance with white point

Now reset all changes on the tab.  We will try to point the program at an object which should be white or gray.

The program will adjust RGB sliders automatically to make this point white or gray on the image too.

To proceed please click on the White balance button and point at the white object:

Important : Do not select too bright or overexposed areas - they are always white and cannot be used to set a correct white balance.

Step 4.  Set white balance using Memory colors

Even on this image I had a problem selecting white but not an overexposed area. There are no white objects in some images.

However, the face tone is often much more important to people then the white color of their shirt.

Helicon Filter has a predefined and  editable list of the most popular colors which people remember quite well - the Memory colors list:

To set white balance using the Memory colors

1. press Memory colors button

2. select a skin area which you want to make look natural

3. select the color in the Memory colors dialog which you would like to apply.

The program will change the RGB sliders so that the selected area has the same hue as the color from the Memory colors list.

Please note, that you can add your own Memory colors (e.g. "My wife's normal skin tone"). To do this please use the button "Add this color" in the Memory colors dialog when it is open.

Step 5.  Save the resulting image.

Original image with a red cast

Resulting image

If you are happy with your result, switch to Save tab and save the result as usual.

If you open the original image later the program will "recall" all parameters that were applied last time. Consequently you will be able to continue editing the original image. To restart from a scratch, reset all settings with button.

If you have any suggestions for changes to Helicon Filter or to the help and tutorials, please contact us at filter@helicon.com.ua

Helicon Soft Ltd. © 2000-2008

How to use the histogram

If you want to produce bright, vivid images you cannot do it without the Histogram.

The histogram shows a distribution of pixels. The number of dark pixels is shown on the left side, the number of bright pixels - on the right side.

A general rule is that a histogram of the resulting image should take all the scale without big "hills" on the sides.

On the image below you can see two images (a source on the left and a result on the right) and two histograms (upper for the source, lower for the result):

I have used the Highlights slider to darken the sky and add some contrast to the clouds.

Now let us go through a step by step tutorial about normalizing the histogram.

Step 1. Open the source image

You can open an image with a usual Open Dialog (menu->File->Open) or you can choose the image from the file browser on the Source tab.

If you would like to experiment with the sample image, I would suggest you copy the image from this page and paste it into Helicon Filter.

Step 2. Analyze the histogram

Once you've opened the image, switch to the Brightness tab. You will see the Equalizer with the Histogram on the left bottom corner of the program. The histogram on the top is the original and the bottom one shows it with the resulting changes."

1. If the Histogram is shifted to the left (dark) side, it means that the image is too dark.

Dark image	The histogram has a hill on the left side

2.  If the Histogram is shifted to the right (bright) side, it means that the image is too bright.

Bright image	The histogram has is shifted to the right

3. If the Histogram has a big hill on the center, it means that the image is properly exposed but it does not use the whole dynamic range and looks too flat.

Flat (low contrast) image	The histogram has is concentrated in the center

4. If the Histogram is pressed to its sides, it means that the image is over- and/or underexposed. The peak on the  right border means that all pixels corresponding to the sky have the same (maximum) brightness. The details (clouds) on the sky are completely lost and cannot be restored by post processing.

The peak on the left corresponds to the pixels in the shadows. Their value is close to 0 and consequently these areas are full with digital noise. If you shoot in RAW format with 16 bit quality and low ISO values to minimize the noise, it is possible to pull the details from the shadows and save the image. If you shoot in JPEG on a compact camera, there is not much hope to get high quality result.

Remember: underexposed image can be saved, overexposed - not!

Flat (low contrast) image	The histogram has is concentrated in the center

The above image is properly exposed but the dynamic range of the scene is too wide for a digital camera so the highlights get overexposed and shadows - underexposed.
The problem can be solved by making two shots with different exposures (one for the sky, second for the shadows).
The two images can be merged by Helicon Filter into one High Dynamic Range (HDR) image with full details on the sky and shadows.

Step 3. Normalize the image

A general rule is to stretch the histogram so it takes all the scale (dynamic range).

This can be done by controls on the brightness tab: Auto contrast, Haze compensation, Local contrast and others.

When changing the brightness, activate Exposure warnings to get alerted if the pixels are pushed over a dynamic range.

1. Normalizing the dark image.

To normalize this dark image I would check the Auto contrast and move the right slider under the checkbox. This will "cut" unused part of the histogram and the program will stretch the rest of it to fill the whole dynamic range. I would also use the Shadows slider to make the green areas a bit brighter without affecting the bright sky. Please keep an eye on the right border of the lower histogram. The number of overexposed pixels near the right border should not be too big!

2. Normalizing the bright image

To normalize this bright image I would use the Haze compensation control at first. Then use the Auto contrast  sliders to "cut" unused part of the histogram. The image definitely needs vignetting correction, which can be done on the Distortions tab later. Please keep an eye on the right border of lower histogram. The number of overexposed pixels near the right border should not be too big!

Step 4.  Save the resulting image.

If you are contented with your result, switch to Save tab and save the result as usual.

If you open the original image later the program will "recall" all parameters that were applied last time. Consequently you will be able to continue editing the original image.

If you have suggestions for changes to Helicon Filter or to the help and tutorials, please contact us at filter@helicon.com.ua

Helicon Soft Ltd. © 2000-2008