any size palette may be used as needed although smaller palettes permit greater compression the values of the palette tags are positive integers greater than zero for example if color 1 is 100 black and color 2 is 100 red the rgb records will read thus the ifm record flags the internal format as format 2 7 with format 1 being reserved for a format under development as follows formats 2 6 are used in the first embodiment of the invention and indicate the size of a reserved color field which size is a constant determined by the number of bits required by the palette the format number is related to the number of colors in the palette thus ______________________________________format number number of colors in palette______________________________________2 2 33 4 74 8 155 16 316 32 63______________________________________ format 7 is implemented in the second embodiment of the invention and is used far palettes of 64 or more colors in format 7 the color bit stream and run length bit stream are separate each bit stream length varies as needed to represent the current value this format permits 34 intelligent 34 rasters the header may also include the following optional records comments begin with an 34 34 exclamation point ost offset represents the number of pixel lines between offset tags ver version represents the version number of the file format currently 1.