Creating high-contrast posterized images
You can condense the brightness variations in an image with the Pos-
terize command. If you apply the Posterize command to a photo-
graph, it creates a high-contrast image by compressing hundreds of
brightness levels into only a few. You set the number of brightness
levels you want to retain, and Canvas reduces each color channel to
that number of values.
The Posterize commands effect depends on the mode of the image
you posterize; e.g., if you apply the Posterize command with a setting
of 2 levels to a grayscale-mode image, the image becomes black and
white. If you apply the same setting to an RGB-mode image (even if
it contains only grays), the command converts each pixels red,
green, and blue value to either zero or full color, reducing the image
to eight colors red, green, blue, red-green, red-blue, blue-green,
black, and white.
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 dont 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
After you enter the Levels setting, click OK.
Original RGB image
Posterize 4 levels
Posterize 2 levels
Posterize 8 levels
Tip
You cant use the Posterize
command on images in
Black & White or Indexed
mode.