Lexmark T642 Technical Reference page 97

The following example prints a Group 4 image file that is 256 bits wide and 9,645 bytes
long:
*b1002M
ESC
*r256S
ESC
*r1A
ESC
*b9645W
ESC
... Group 4 image data
[
*rB
ESC
All lines of data must be the same length. If they are not, zeroes (0) must be added to
attain the same length.
Note:
Additional Compression Modes
When the compression mode is 1008 (Lexmark Adaptive), TIFF word and double-
word can be printed using compression scan modes 254 and 255 respectively. This
compression method sends a raster image as a block of raster data.
...
]
If the uncompressed image extends beyond the logical page dimensions or
beyond the raster width specified in the Raster Width command (
image is clipped at print time.
2-84
|Set Raster Compression to Group 4
|Define width of image in input bits
|Start Raster Graphics at current position
|9,645 bytes of a Group 4 image
|End Raster Graphics
PCL
ESC ), the
*r#S