HP PCL/PJL reference (PCL 5 Color) - Technical Reference Manual

EN Modifying Output Color (Color LaserJet, 5, 5M, DeskJet) D-7
A user-defined matrix is defined in additive colors (RGB values). The
dither matrix pixels are defined in terms of device-dependent
resolution.
When using the Download Dither Matrix command, you have several
options:
• You can choose whether to define a separate matrix for each
color plane, or use the same matrix for all three color planes.
• You set the height and width of the dither cell. When using
separate matrices for each plane, you can use different size
dither cells for each plane. For example, you can have a 4 x 4
pixel cell for red, a 4 x 6 cell for green, and a 6 x 8 cell for blue.
• You download the data bytes for each pixel of the cell. Each
data byte determines a threshold—every pixel with a value
greater than or equal to the threshold gets turned on and every
pixel with a value less than the threshold does not get turned
on.
Note HP Color LaserJet 5 and 5M printers do not support user-defined
dithers. When a Download Dither Matrix command is sent, the printer
parses and discards the matrix data and selects the continuous tone
smooth 150 lpi algorithm instead.
Download Dither Matrix Command
The Download Dither Matrix command specifies a single matrix for all
three primary colors, or three matrices (one for each primary), which
may have different sizes and contents.
?*m#W[data]
# = Number of bytes of byte-aligned binary data in the data
field
Default =0
Range = 7 to 32767 (command is ignored for values of 0 – 6;
values larger than 32767 or device limits are clamped;
signs are ignored)