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

3-6 Using Palettes EN
Management by ID allows applications to tag data, have multiple
raster configurations, and have palettes for different color spaces—all
without reconfiguring the active palette. For example, one palette can
be created for PCL text, one for HP-GL/2 primitives, one for simple
raster, and one for 24-bit raster. The application can then switch
between palettes according to what is being sent to the printer.
Selecting a new active palette changes the PCL graphics state.
Besides the color entries, a palette also has the graphics state which
contains the color space, color treatment, and render algorithm. This
ensures that the same color specification in a given palette will always
produce the same printed color.
As described below, the Select Palette (
?&p#S), Palette Control
(
?&p#C), and Palette Control ID (?&p#I) commands implement the
three basic operations of management by ID.
• Selection of the active palette
• Deletion of palettes
• Copying of palettes
Select Palette Command
The Select Palette command selects a new active palette by
specifying an ID number. The previously active palette is unchanged.
?&p#S
This command activates the designated palette in the palette store.
The command is ignored if the specified ID matches the active
palette's ID, or if no palette with that ID exists. The designated ID is
saved as the palette select ID for the duration of the print job, or until
another Select Palette command is received.
This command can be used to de-select the active palette and select
as the new active palette a palette created by the Palette Control
command (
?&p#C). For example, to copy the active palette to an ID
of 44 and select the new palette to use or modify, send
?&p44i6c44S.
# = Palette ID number
Default =0
Range = 0 to 32767 (command is ignored for out- of-range
values)