Data Compression


Criteria

Survey Formats

Basics

Compression Methods

Data Formats


Run Length Encoding

General Principle

Control Characters

RLE for Image Data

Implementations

MS-Windows .bmp RLE8

Encoded Mode

Absolute Mode

Marker

Example "B"

MS-Windows .bmp RLE4


Glossary

Index


Download


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Encoded Mode


In encoded mode data have the general form counter plus symbol. Any initial value in a range of 1 to 255 identifies the encode mode and will be regarded as a counter assigned to the symbol following consecutively. If the intial value of a code word is 0, either a marker or data coded in absolute mode follow.


Coding scheme encoded mode:




Example:

encoded   decoded
  01 00   00
  02 00   00 00
  04 00   00 00 00 00
  0A FF   FF FF FF FF FF FF FF FF FF FF

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MS-Windows .bmp RLE8 MS-Windows .bmp RLE8 Absolute Mode