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

6-34 Raster Graphics EN
The value field (#) identifies the number of bytes in the raster row.
These bytes are interpreted as one row of raster graphics data
printed at the current Y position at the left raster graphics margin.
Upon completion of this command, the cursor position is at the
beginning of the next raster row at the left raster graphics margin.
Raster graphics are independent of the text area and perforation skip
mode—these boundaries are ignored.
Raster graphic images, raster height, and raster width are limited to
the printable area; images that extend beyond the printable area are
clipped.
Byte Counts and the TIFF v4.0 Compression Mode
The byte count of the value field in the Transfer Raster Data command
has precedence over the literal, or the command byte, byte count of
the TIFF v. 4.0 compression mode. For example, the command,
?*b2m3W [binary data]
sets compression method=2 (TIFF v. 4.0) and sends 3 bytes of raster
data for the row. Suppose the binary data appears as follows:
00000010 00000001 00000001 00000001
The control (first) byte value of 2 indicates that 3 bytes of literal
(unencoded) raster data will follow. The Transfer Raster Data
command, however, specified only three bytes total (including the
control byte) in the raster row. The control byte and the following two
data bytes are read, and the remaining data byte is ignored.
If the last byte indicated by the value field in the Transfer Raster Data
command is a control byte, that byte is ignored.
Note If a Transfer Raster Data command is received without an
accompanying Start Raster Graphics command, any preceding start
raster values are used (such as left graphics margin, raster height
and width, etc.).