An image representation in which each pixel is represented by a single sample that is an index into a palette or lookup table. The selected palette entry defines the actual color of the pixel.
In PhotoShop, an image mode in which there is only one channel and a color table that can contain up to 256 colors. All the colors in an Indexed Color image are displayed on its table--unlike an image in any other mode.
Refers to graphics. Most web graphics are made up of colors from a palette that contains 256 RGB colors. If the colors used in the graphic are not part of the limited palatte, the colors appear dithered on 8 bit monitors.
A way to produce images for the Web while minimizing the number of colors (and therefore the file size). Indexed color is a palette of up to 256 colors and is used for GIFs.
A color system that uses information from a file or from software as a pointer to look-up colors from a table rather than specifying a color directly. Color specified from a 24-bit palette but displayed in an 8-bit system is an indexed color.
Another term used to describe palette-based images; synonyms include colormapped and pseudocolor.
color model where color information is stored in a lookup table instead of in individual pixels. Each pixel will have an indexed reference to the table to denote its color. Indexed color images can have at most 256 colors. GIF files use an indexed color model.
Reduced Color mapping, 8 bit or less. Done to reduce images to their smallest size. Commonly used for images placed on home pages of the Internet. The 256 color palette are also mapped for best results on the Internet, taking into account the differences between the Windows and Macintosh color palettes. (Also see GIF, GIF 89a, BMP).
A color image format that contains a palette of 256 colors or less to define the image. Indexed color can reduce file size while maintaining visual quality. The reduction in file size makes it an ideal format for multimedia or web graphics. It is not used for high end printing.
A color system that defines a palate of colors to be used in a specific image. Often this makes images small and manageable.
Indexed color is a type of color space for digital images. Whereas an RGB image specifies a red, green, and blue value separately for each pixel in the image, an indexed color image maintains a table that defines a number of predefined colors, and each pixel refers to a color in that table.