PCL
2-81
Run-Length Encoded Data
Run-Length Encoded Data is interpreted in pairs of bytes. The first byte:
•
Acts as a counter, or control byte.
•
Indicates how many times to repeat the data in the second byte.
•
Can be from 0 (no repetition) to 255.
•
The second byte is the data byte.
Example:
ESC
*p300x600Y
|Move cursor to 1" x 2"
ESC
*b1M
|Set compression to Run-Length
ESC
*r1A
|Start raster graphics at current position
ESC
*b2W '07FF'x
|Run-Length: 8x'FF'x
ESC
*b6W '0080 0500 0001'x
|1x'80'x, 6x'00'x, 1x'01'x
ESC
*b6W '0080 0500 0001'x
|1x'80'x, 6x'00'x, 1x'01'x
...
|
...
ESC
*b6W '0080 0500 0001'x
|1x'80'x, 6x'00'x, 1x'01'x
ESC
*b2W '07FF'x
|8x'FF'x
ESC
*rB
|End graphics
Tagged Image File Format
TIFF “Packbits” contain a control byte (a signed number) that indicates whether the
raster data bytes are to be repeated (up to 127 times) or printed as encoded data.
•
For control values of 0 through 127, the next (1) byte(s) is uncoded.
•
For control values of -1 through -127 ('FF'x - '81'x), the next byte is repeated
(Abs(C1) times.
Example:
ESC
*p300x900Y
|Move cursor to 1" x 3"
ESC
*b2M
|Set compression to TIFF
ESC
*r1A
|Start Raster Graphics at current position
ESC
*b2W 'F9FF'x
| TIFF: 8x'FF'x
ESC
*b6W '0080 FB00 0001'x
|1:'80'x, 6x'00'x, 1: '01'x or
ESC
*b9W '078000000000000001'x
|8: '8000000000000001'x
...
|
...
ESC
*b6W '0080 FB00 0001'x
|1:'80'x, 6x'00'x, 1: '01'x
ESC
*b2W 'F9FF'x
|8x'FF'x
ESC
*rB
|End graphics
