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

MS-Windows .bmp RLE4

Example "B"

"B" uncompressed


Glossary

Index


Download


www.BinaryEssence.com

Example "B" uncompressed with 16 colours



Encoded data:


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

  • 16 colours
  • Colour index 0: black
  • Colour index 1: white
  • 15 lines
  • 15 pixels per line
  • Lines extended to 16 pixels
  • Extended pixels set to colour index 0
  • File size including header and colour table: 238 byte
  • File size data area: 120 byte

 <   ^   > 

Example B compressed according to RLE4 Example B compressed according to RLE4 Run Length Encoding