Lexmark C762 User Manual
PCL
2-63
Delta Row
Delta Row is a
compression mode that identifies and transmits only those bytes
different from the ones in a preceding row. The control byte consists of two parts:
•
High 3 bits: Number of bytes to replace +1 (1 to 8).
•
Low 5 bits: Offset from last unmodified byte (0-30); if the offset is 31, the next
byte(s) is added to the offset until the next byte is not 255.
byte(s) is added to the offset until the next byte is not 255.
Example:
ESC
*p300x1200Y
|Move cursor to 1" x 4"
ESC
*b3M
|Set compression to Delta Row
ESC
*r1A
|Start raster graphics at current position
|Num Offset
|Num Offset
ESC
*b9W 'E0FFFFFFFFFFFFFFFF'x
|'111 00000'b=8 at 0: 'FFFFFFFFFFFFFFFF'x
ESC
*b9W 'E08000000000000001'x
|8 at 0: '8000000000000001'x
ESC
*b0W
|No bytes change
...
ESC
*b0W
|No bytes change
ESC
*b9W 'E0FFFFFFFFFFFFFFFF'x
|8 at 0: '8FFFFFFFFFFFFFF'x
ESC
*rB
|End graphics