HP L 5 manual Color Lookup Tables Command

Color Lookup Tables

Color lookup tables provide a way to re-map color data for the following types of applications:

•Highlight and shadow modification

•Saturation and desaturation

•Unique gamma correction curves

•Special effects for tonal correction

•Neutral balancing

Color lookup tables map input data for each primary color into a new output range based on point-by-point conversions. Color lookup tables can modify input data for both device-dependent and device-independent color spaces.

Like the CID command, the first byte of the data field identifies the color space to which the lookup tables will be applied. These tables specify on a point-per-point basis a transformation from an input space of 0 . . . 255 into an output space of 0 . . . 255. Figure D-1 on the next page illustrates the concept.

The unity lookup table (see the following illustration) is the default for all color spaces; it performs a 1:1 mapping of input to output (that is, 129 is mapped to 129). The inversion lookup table performs a simple color inversion; for example, it inverts the red primary of a device-dependent RGB color space to create cyan output (from 255 red to 0 red, which is 255 cyan).

Color Lookup Tables Command

This command enables and specifies color lookup tables.

?*l#W[binary data]

#= Number of bytes of binary data

Default	=	0
Range	=	0 or 770 (command is ignored for other values; sign is
		ignored)

A value of 0 resets or initializes the color lookup tables for each primary to the unity curve (1:1). A value of 770 means the data for a color lookup table will be following. The command is ignored and the data is absorbed for any number of bytes not equal to 0 or 770.

EN Modifying Output Color (Color LaserJet, 5, 5M, DeskJet) D-13