while preserving luminosity details. Programs displaying the image
will upsample to the original resolution, so greater compression is
achieved without changing the display resolution of the image.
Optimized
This option can help produce smaller file sizes. When
Optimized is selected, some of the least important color information
is discarded to produce more efficient compression.
GIF options
To use GIF format, select GIF from the Format menu. Canvas applies
the GIF format and settings to the active preview pane.
Max colors
Use the menu or type in the box to specify the maxi-
mum number of colors to be used in the image. Fewer colors can
result in a smaller file, but too few colors will degrade an image.
Palette
A palette is a set of colors used in an image. To be saved in
GIF format, an image can contain no more than 256 colors. If the
image contains more colors, the original colors are mapped to the
colors in the palette that you choose.
Adaptive creates a palette that tries to match as close as possi-
ble all the colors in the image. This option is the best for pre-
serving the original color range of an image.
Web uses a standard color palette supported by major web
browsers. The range of colors in the web palette, however, can
cause color shifts in images with many shades of a few colors.
Uniform uses a palette of colors that are uniformly distributed
through the range of possible RGB colors.
Exact creates a palette from the actual colors in the image, if
the image contains fewer than 256 colors. If the image contains
more than 256 colors, Canvas uses the Adaptive option.
Note: To apply a custom or system color palette to a paint object
before saving in GIF format, select the paint object and choose Image
> Mode > Indexed. In the dialog box, select a palette option and click
OK. To modify an Indexed mode paint object, choose Image >
Mode > Color Table.