IBM 1725 SLS - Manual (Page 272)

CCITT
Commands
QMS 1725 SLS Print System User's Guide C-22
Compression
DPI
ImageData
Default false
Function Sets the data compression type of the data following the
%%ImageData command.
Syntax %%Compression (type)
type 0Group 4
1Group 3, 1-dimensional
2Group 3, 2-dimensional
Default 0 (Group 4)
Function Sets the print resolution to match the scanned resolution of the
original image. This command can also be used to scale the
image. DPI resolutions above the original scanned resolution will
reduce the image while DPI resolutions below the original
scanned resolution will enlarge the image.
Syntax %%DPI (horizontal vertical)
horizontal
vertical
Default Currently selected engine resolution.
Function Instructs the emulation to begin decompression of the image
data using the currently set image options. This command begins
reading the image data after the end of the current line. After the
image, the input stream is flushed until the next set of %%
characters is encountered.
Syntax %%ImageData
Default None—no options.
Notes You must specify %%ImageSize before %%ImageData. If you
do not, the data following %%ImageData is absorbed with no
effect on the file.