ABSTRACT
Data communication increasingly involves the transmission of still and moving images. Great savings in the number of bits can be made by compressing the images into a standard form. Some of these forms are outlined in Table 4.1. The main parameters in a graphics file are:
The picture resolution. This is defined by the number of pixels in the xand y-directions.
The number of colors per pixel. If N bits are used for the bit color then the total number of displayable colors will be 2 N . For example an 8-bit color field defines 256 colors, a 24-bit color field gives 224 or 16.7M colors.
Palette size. Some systems reduce the number of bits used to display a color by reducing the number of displayable colors for a given palette size.
