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"

"B" uncompressed

MS-Windows .bmp RLE4


Glossary

Index


Download


www.BinaryEssence.com

Example "B" uncompressed with 256 colours



Encoded Data:


    0  1  2  3  4  5  6  7  8  9 10 11 12 13 14
14 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 00
13 FF FF 00 00 00 00 00 00 00 00 00 FF FF FF FF 00
12 FF FF FF FF 00 00 00 FF FF FF 00 00 FF FF FF 00
11 FF FF FF FF 00 00 00 FF FF FF FF 00 00 FF FF 00
10 FF FF FF FF 00 00 00 FF FF FF FF 00 00 FF FF 00
 9 FF FF FF FF 00 00 00 FF FF FF FF 00 00 FF FF 00
 8 FF FF FF FF 00 00 00 FF FF FF 00 00 FF FF FF 00
 7 FF FF FF FF 00 00 00 FF 00 00 00 FF FF FF FF 00
 6 FF FF FF FF 00 00 00 FF 00 00 00 FF FF FF FF 00
 5 FF FF FF FF 00 00 00 FF FF FF 00 00 FF FF FF 00
 4 FF FF FF FF 00 00 00 FF FF FF FF 00 00 FF FF 00
 3 FF FF FF FF 00 00 00 FF FF FF FF 00 00 FF FF 00
 2 FF FF FF FF 00 00 00 FF FF FF 00 00 00 FF FF 00
 1 FF FF 00 00 00 00 00 00 00 00 00 00 FF FF FF 00
 0 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 00

  • 256 colours
  • Colour index 00: black
  • Colour index FF: white
  • 15 lines
  • 15 pixels per line
  • Lines extended to 16 pixels
  • Extended pixels set to colour index 00
  • File size including header and colour table: 1.318 byte
  • File size data area: 300 byte

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Example B compressed according to RLE8 Example B compressed according to RLE8 MS-Windows .bmp RLE4