DCT Image Compression

A Python implementation of image compression using Discrete Cosine Transform (DCT) and OpenCV. To measure compression, I saved both of the pictures as np arrays and looked at the file size.

This is an educational project, currently I am using the cv2 inbuild dct and idct functions because my naive python rebuild is too slow, but the project will be further extended with my own fast-DCT implementation in C.

Setup

python3 -m venv .venv
source .venv/bin/activate  # On Windows: .venv\Scripts\activate
pip install -r requirements.txt

Usage

Place your image as test_img.png in the project directory and run:

python main.py

Process

1. Compression: Padding → Shift → DCT-II → Quantization
2. Decompression: Quantization → DCT-III → Shift

License

MIT