APPENDICES
CCITT G3/G4 and TIFF (original command)
One of the unique features of the PCL mode of this printer is it supports CCITT G3/G4 type data compression and TIFF format.
■CCITT G3/G4 (Raster Graphic Mode 1152)
The printer’s PCL mode supports CCITT G3/G4 type graphic data compression.
This format is popular in optical document storage area as this compression is effective to store black and white type pictures.
Compression mode for CCITT G3/G4 is 1152 and the command becomes ESC * b 1152 M.
As G3/G4 format does not have picture size/resolution information, the printer requires a header at the beginning of the picture data. The header size is 94 byte. Both the header and the picture data are transferred by one transfer graphics data command (ESC * b ### W). Normal PCL transfer graphics data command has a limitation of the data size and ### should not exceed 32767. Unlike other mode, mode 1152 is special and this mode does not have 32767 byte size limitation.
Print model is not applied to this type of raster graphics.
The mode 1152 graphic data consists of the following data structure. The picture data follows the header.
Header
CCITT G3/G4 Picture Data
94 bytes |
|
| File length |
Picture | = #### |
data | of ESC*b####W |
length |
|
Header format is described on the next page.
You have to specify mode 1152 by sending ESC *b1152M command for each graphic data transfer.
About CCITT G3/G4 data format, please refer to CCITT (THE
INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE) BLUE BOOK Volume VII.
