Demo result

Zoom them yourself to see the differences.

• Image before compression: 6000 x 3376 , 11,6MB
• Image after compression: 1,23MB

Project Structure: classes

• Main:
  • Create path to input image, output location
  • Call JPEG_Compress class
• JPEG_Compress
  • Read Image from path get from Main
  • Compress
  • Export to output path get from Main
• BitCode
  • A class for a huffman code, contain 2 atributes: code word and number of bit that demonstrates the code word
• BitBuffer
  • A class use to store bit sequence generated in Run Length Encoding and Huffman Encoding processes.
  • It contains 2 atributes: the buffer (a int number), and the number of bit that still in the buffer, waiting there to write out.

Technical espects

• 
• JPG file structure
• Use default quantization table for 50% quality lost.
• Use standard huffman table that encodes the length of value instead of value it self.
• Works with: 3 color system image.
• No subsampling
• JFIF : 1.1
• It works well when compress larg size image, bring a high compression ratio, but it has a really little effect on small size image.
• Works well with non-text image.

Issues

1. UI: we have no UI, this should be consider at last.
2. Bad performance (comment the console log to avoid IO block, increase performance)

Documents

• Theory
  • T? tìm hi?u, l?n r?i, không bi?t google à, th?y t? b?o th?
  • blog 1
  • blog 2
  • video
• Coding
  • Huffman encoding
  • source code C++