Lexmark C760, C762 manual Run-Length Encoded Data, Tagged Image File Format

2-62 PCL

Run-Length Encoded Data

Run-Length Encoded Data is interpreted in pairs of bytes. The first byte:

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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 (Control+1) byte(s) is uncoded.

•For control values of -1 through -127 ('FF'x - '81'x), the next byte is repeated (Abs(Control)+1) 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