qoi/README.md

qoi-fast

Fast encoder/decoder for QOI image format, implemented in pure and safe Rust.

• One of the fastest QOI encoders/decoders out there.
• Compliant with the latest QOI format specification.
• Zero unsafe code.
• Supports decoding from / encoding to std::io streams directly.
• no_std support.
• Roundtrip-tested vs the reference C implementation; fuzz-tested.

Examples

use qoi_fast::{encode_to_vec, decode_to_vec};

let encoded = encode_to_vec(&pixels, width, height)?;
let (header, decoded) = decode_to_vec(&encoded)?;

assert_eq!(header.width, width);
assert_eq!(header.height, height);
assert_eq!(decoded, pixels);

Benchmarks

Comparison to the reference C implementation (as of 00e34217), benchmarks timings collected on Apple M1 (1782 images, 1187 MB total):

codec          decode:ms    encode:ms  decode:mp/s  encode:mp/s

qoi-c            4389.75      5524.18        283.5        225.3
qoi-fast         3026.68      4304.26        411.2        289.2

Benchmarks have also been run for all of the other Rust implementations of QOI for comparison purposes and, at the time of writing this document, this library proved to be the fastest one by a noticeable margin.

no_std

This crate supports no_std mode. By default, std is enabled via the std feature. You can deactivate the default-features to target core instead. In that case anything related to std::io, std::error::Error and heap allocations is disabled. There is an additional alloc feature that can be activated to bring back the support for heap allocations.

License

This project is dual-licensed under MIT and Apache 2.0.