pixo

A minimal-dependency, high-performance image compression library written in Rust.

Learn more about this project.

Features

• Zero runtime dependencies — All encoding algorithms implemented from scratch
• Entirely in Rust — No C or C++ codecs required
• PNG and JPEG support — Lossless PNG, lossy PNG (quantization), and lossy JPEG
• Small WASM binary — 159 KB with competitive compression (benchmarks)
• Well-tested — 86% code coverage, 965 tests (codebase comparison)

Usage

1. Playground (recommended) — Try it in your browser
2. WASM — Use in browser or Node.js applications
3. CLI — Compress images from the command line
4. Rust Crate — Use as a library in your Rust projects

Documentation

Comprehensive guides explaining the algorithms and compression strategies:

• Introduction to Image Compression — Why and how we compress images
• Introduction to Rust — Rust features through the lens of pixo

Core Algorithms

• Huffman Coding — Variable-length codes based on symbol frequency
• LZ77 Compression — Dictionary-based compression with sliding windows
• DEFLATE Algorithm — How LZ77 and Huffman combine

Image Formats

• PNG Encoding — Lossless compression with predictive filtering
• JPEG Encoding — Lossy compression pipeline
• Discrete Cosine Transform — The mathematical heart of JPEG
• Quantization — How JPEG achieves compression