JPEG-Codec

Brief

• Reference from JPEG Tutorial by MROS

• C++ Implementation

• Use optimizations as described below

  • Canonical Huffman Code with pre-compute look-up index

  • Dimension Reduction IDCT from to

  • In place swap dezigzag

File structure

• Segment.cpp - Define how each segment read jpg data
• Decoder.cpp - Decode compressed data using de-quantization, de-Zigzag, Inverse DCT, Upsampling

Output

• Use .bmp as output format

Setup

mkdir -p cmake/build
cd cmake/build
cmake ../../
make

The generated binary will be in cmake/build directory

Usage

• Decode

main -i [input file name] (-o output file name)

or

main [input file name]

Environment

• Testing
  • CPU: Intel Core i7-8750H CPU
  • Operating System: Windows 10 64-bit
  • Memory: 32GB
• Build
  • GCC Version: 6.3.0
  • CMake Version: 3.16.5

TODO

• handle RSTn in compressed data section