https://github.com/image-rs/fdeflate

Fast deflate implementation specialized for PNG image data
https://github.com/image-rs/fdeflate

Last synced: 3 months ago
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Fast deflate implementation specialized for PNG image data

• Host: GitHub
• URL: https://github.com/image-rs/fdeflate
• Owner: image-rs
• License: apache-2.0
• Created: 2022-12-18T23:15:38.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2025-01-13T22:44:51.000Z (5 months ago)
• Last Synced: 2025-03-29T11:09:13.142Z (3 months ago)
• Language: Rust
• Size: 167 KB
• Stars: 19
• Watchers: 5
• Forks: 4
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGES.md
  • License: LICENSE-APACHE

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README

        
# fdeflate

[![crates.io](https://img.shields.io/crates/v/fdeflate.svg)](https://crates.io/crates/fdeflate)

[![Documentation](https://docs.rs/fdeflate/badge.svg)](https://docs.rs/fdeflate)

[![Build Status](https://img.shields.io/github/actions/workflow/status/image-rs/fdeflate/rust.yml?label=Rust%20CI)](https://github.com/image-rs/fdeflate/actions)

A fast and safe deflate implementation for PNG.

This crate contains an optimized implementation of the [deflate algorithm](https://en.wikipedia.org/wiki/Deflate) tuned for PNG images.

At least on PNG data, our decoder rivals the performance of `zlib-ng` and `zlib-rs` without using any `unsafe` code.

When compressing it makes a bunch of simplifying assumptions that

drastically improve encoding speed while still being compatible with zlib:

- Exactly one block per deflate stream.

- No distance codes except for run length encoding of zeros.

- A single fixed huffman tree trained on a large corpus of PNG images.

- All huffman codes are <= 12 bits.

### Inspiration

The algorithms in this crate take inspiration from multiple sources:

* [fpnge](https://github.com/veluca93/fpnge)

* [zune-inflate](https://github.com/etemesi254/zune-image/tree/main/zune-inflate)

* [RealTime Data Compression blog](https://fastcompression.blogspot.com/2015/10/huffman-revisited-part-4-multi-bytes.html)