HP 5961-0509 manual Examples Run-length and Tiff Compression, Byte Number Bits

Models: 5961-0509

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TIFF encoding also allows you to include a non-operative (NOP) control byte, represented by the value –128. This byte is ignored, and the subsequent byte is treated as the new control byte.

Note

It is more efficient to code two consecutive identical bytes as a

 

repeated byte. If these bytes are preceded and followed by literal

 

bytes, however, it is more efficient to code the entire group as literal

 

bytes.

 

 

Examples: Run-length and TIFF Compression

The following examples show how a raster row can be coded using run-length and TIFF compression methods. Note that the compression examples use characters to represent the binary data stream.

Table 15-6

Byte

#1

#2

#3

#4

#5

#6

#7

Number

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bits

01010101

01010101

01010101

01010101

01000001

01010100

01010100

 

 

 

 

 

 

 

 

ASCII

U

U

U

U

A

T

T

 

 

 

 

 

 

 

 

Unencoded

EC*r1A

EC*b0m7WUUUUATT

EC*rC

Run-length Encoding

EC*r1A

EC*b1m6W(3)U(0)A(1)T

EC*rC

EN

Set Compression Method Command 15-19

Page 327
Image 327
HP 5961-0509 manual Examples Run-length and Tiff Compression, Byte Number Bits