User Guide

Chapter 5: Painting And Image Editing
To posterize an image:
1. Select one or more paint objects to posterize all the images. You can select an area in one
image in edit mode to posterize the selected area only. If you don’t make a selection, the
entire image is affected.
2. Choose Image | Adjust | Posterize.
3. Enter a level from 2 to 255. Higher numbers produce subtle effects. Lower numbers produce
high-contrast images.
4. Click OK after you enter the Levels setting.
Changing color and contrast
You can use the Invert, Desaturate, and Brightness/Contrast commands to create special effects and
correct lightness levels in images. These commands apply changes equally to all color values.
If you select an area of an image, Canvas applies the command to that area only. Otherwise, Canvas
applies the command to the entire image in a paint object.
Inverting colors in images
You can use the Invert command to reverse the colors in an image, as in a photographic negative.
The command converts each pixel’s color to its opposite hue in the color spectrum. It does this by
inverting the brightness value of each pixel in each color channel.
For example, if a pixel is pure red, its brightness levels are 255, 0, 0 in RGB mode. When inverted,
this pixel’s brightness values become 0, 255, 255, changing it to pure blue-green, its opposite in
hue.
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