gif.py

Attempt to create a gif decoder

decoder

• Header
• Logical Screen Descriptor
• Global Color Table
• Extentions:
• • Graphic Control Extension
• • Comment Extension
• • Plain Text Extension
• • Application Extension
• Image Descriptor
• Local Color Table
• Image Data

viewer

• Global Color Table
• Local Color Table of first image
• First image
• Local Color Table of other images
• Other images
• Animation
• Background fill with Background Color
• Ignore Transparency Color
• Disposal Methods
• Text rendering by Plain Text Extension

Usage

.\gif.py sample.gif

It will create gif_data.js that include decoded color table and index stream of image
To view decoded color table and image open viewer.html

References

GIF specification GIF87a
GIF specification GIF89a
3MF Project: What's In A GIF - Bit by Byte