Brother HL- SERIES, Technical Reference Manual, Page: 98 / 392

Revision C 16/01/96
Chapter 2 "PCL" - 83
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# = 1152 indicates that CCITT G3/G4 data compression is to be used.
This format is popular in optical document storage area as this compression is effective to store black and
white type pictures. 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. Bothe the header and the picture data
are transferred by the ESC*b###W(###=data length) command. Normal PCL transfer graphics data command
has a limitatino of the data size and ### should not exceed 32767. Unlike other mode, this mode is special
and does not have the 32767 size limitation. The data must have the following structure - Header and Picture
data. The values in this mode are little endians.
Byte
position Data Description
0 - 1 6E 6E 'nn' This is header ID.
2 - 3 0A 00 Reserved
4 - 7 5E 00 00 00 Picture data start offset from header top
8 - 11 File length File length including 94 Byte header. If file length is 65,536
byte, these 4 bytes become "00 00 01 00"
12 - 13 01 00 Reserved
14 - 15 01 00 Reserved
16 - 19 4A 00 00 00 Reserved
20 - 21 Compression mode 02 00: Fax MH format
03 00: Fax MR format
04 00: Fax G4 format
22 - 55 00 ... 00 All zero
56 - 59 Picture data length If picture data length is 65,442 (65,536 ~-94) byte, these 4 bytes
become "A2 FF 00 00."
60 - 61 01 00 bit / pixel
62 - 63 01 00 bit / pixel
64 - 65 Pixels/line If picture dot width = 2,400, these 2 bytes become "60 09"
66 - 67 Pixels/line Same as above.
68- 69 Lines/picture If picture dot count = 3,100, these 2 bytes become "1C 0C."
71 - 71 Lines/picture Same as above.
72 - 73 00 00 Reserved
74 - 75 Photometrics 00 00
or 01 00 00 00 : data 0 = white
01 00 : data 0 = black
76 - 77 02 00 Reserved
78 - 79 Fill order 01 00 or
02 00 01 00 : filled from MSB
02 00 : filled from LSB
80 - 81 01 00 Reserved
82 - 83 00 00 Reserved
84 - 85 01 00 Reserved
86 - 87 Resolution 200,
300, 400, 600 C8 00 00 00 : 200 dpi, 2C 01 00 00 : 300 dpi,
90 01 00 00 : 400 dpi, 58 02 00 00 : 600 dpi
400 and 600 dpi are available when printer operates in 600 dpi.
88 - 89 Resolution 200,
300, 400, 600 C8 00 00 00 : 200 dpi, 2C 01 00 00 : 300 dpi,
90 01 00 00 : 400 dpi, 58 02 00 00 : 600 dpi
400 and 600 dpi are available when printer operates in 600 dpi.
90 - 91 02 00 Reserved
92 - 93 00 00 Reserved
About CCITT G3/G4 data format, please refer to CCITT (The International Telegraph and Telephone
Consultative Committee) BLUE BOOK Volume VII.
Header
Picture data
94 bytes
Picture
data
length
File Length