Changing color and contrast You can use the Invert, Desaturate, and Brightness/Contrast com- mands 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. The Invert command can be particularly useful in channel editing, as colored pixels can denote either masked or selected areas. To invert an image 1 Select one or more paint objects to invert all the images. You can select an area in one image in edit mode to invert the selected area only. If you don’t make a selection, the entire image in edit mode is affected. 2 Choose Image > Adjust > Invert. Desaturating image colors You can use the Desaturate command to remove color from images completely, while retaining the relative brightness levels of shadows, Original RGB Inverted RGB Inverted Green channel Green channel selected Tip You can’t use the Invert command on images in Indexed mode.
Canvas 8 Help: Image adjustment and correction (5 of 24)                                            Page #687