It's All About Color: Color extraction and manipulation in PSP9
Note: The activity is not available in Paint Shop Pro Studio

This document describes a method of processing color photographs to achieve interesting effects based on the extraction of pure color information.  From long exposure to "black-and-white" photographs, motion pictures, and television images, we're all familiar with the concept of "grayscale" images, in which only the lightness range of a scene is preserved and the color is discarded.  But what would be the converse of this operation?  That is, what would it look like if we removed the lightness range from a color photograph but left all the color information?  There is no familiar everyday analog of this process, but it is possible to do it in photo editing software such as Paint Shop Pro, and the results can be very interesting.  Here's the process.

1. Open a color photograph that you wish to experiment with, for example "BandAfter" in the "Before and After" folder.

2. Select Image => Split Channel =>  Split to HSL. This creates three grayscale images labeled "Hue...", "Saturation...", and "Lightness...".

3. Select the Flood Fill tool  . Open the Tool Options box and set the "Blend mode" to Normal and the "Match mode" to Opacity. Click on the Color Palette to select a a middle gray color (exact shade is unimportant) and then click on the "Lightness" image. This makes it a solid gray picture.

4. Select Image =>  Combine Channel =>  Combine from HSL and click OK. This will recombine the three grayscale images into a new image, labeled "Image...", that contains only the color information, minus the lighness information. Don't worry if this image looks very dull and flat.

5. You can now close (and don't save) all the images except the one labeled "Image..."

6. With the new image selected, select Adjust =>  Color Balance => Fade Correction. Set the Amount of correction to 90 and click OK.  This will re-balance the color in the image and increase the color saturation.  The result should be a rather flattened, but very colorful, rendition of the original image, in which the main shapes are recognizable but the colors drastically modified and brightened.  An example of this effect is "Color Extraction.jpg" in  the Artistic Effects folder.

7. There are several possibilities for further manipulation.  Posterizing produces interesting graphic-arts effects.  First, select Adjust => Blur =>  Blur More to reduce the detail in the image.  Than select Effects => Artistic Effects => Posterize.  Experiment with different amounts of bluring and with the Levels control in the posterize dialog box.  Don't forget you can always use the "undo" command to undo any number of steps and try something different. 

If you wish to save a posterized image, save it as a gif file:  File => Save As... and select "Compuserve Graphics Interchange (*.gif)" from the "Save As Type" pop-up menu.  Answer YES to the question about saving only 256 colors.  For posterized images, a gif file will look cleaner (no compression artifacts) and will usually be smaller than a jpg file. This is the way that I produced "CE Posterized.gif", "Image23.gif", "Image25.gif", and "Image27.gif" in the Artistic Effects folder.

8. Another possibility is applying a brush stroke effect ( Effects => Art Media effects => Brush Strokes).   This is the way that I produced "Image33.jpg" in the Artistic Effects folder.  Save as a jpg file.

9. Or you might try fine-tuning the color, by selecting Adjust => Hue and Saturation => Hue/Saturation/Lightness and make sure the Colorize box is not checked.  Adjust the sliders to change the color and click OK.  On posterized images, you can use Colors => Adjust => Hue Map to adjust the hue of individual colors all over the image.

Note: The term "HSL" (in step 2) means Hue, Saturation, and Lightness.  To appreciate what these terms mean, click on one of the small color boxes just above the Color Palette.  This brings up the Color dialog box.  Note the color wheel surrounding the color box.  Dragging the mouse along the color wheel changes the Hue; dragging the mouse back and forth in the color box changes the Saturation. and dragging the mouse up and down in the color box changes the Lightness. 
(c) Tom O'Haver, February 2005