libjpeg-turbo-rs

Pure Rust reimplementation of libjpeg-turbo with NEON/AVX2 SIMD acceleration. No C dependencies, no unsafe FFI — just cargo add.

Performance

x86_64 (AVX2)

Benchmarked against C libjpeg-turbo 3.1.0 on x86_64 (AVX2), quality 75:

Decoding

Encoding

aarch64 (NEON)

Benchmarked against C libjpeg-turbo 3.1.0 on Apple Silicon (aarch64 NEON), quality 75:

Decoding (1920x1080)

Encoding (1920x1080)

Decoding matches or beats C on both platforms at larger resolutions. Encoding is near-parity on aarch64; x86_64 encoding has room for further SIMD optimization (Huffman coding). See docs/ENCODING_PERFORMANCE.md for full results.

Quick Start

[dependencies]
libjpeg-turbo-rs = "0.1"

Decompress

use libjpeg_turbo_rs::{decompress, decompress_to, PixelFormat};

// Decode to RGB
let img = decompress(&jpeg_bytes)?;
println!("{}x{}", img.width, img.height);

// Decode to specific format
let img = decompress_to(&jpeg_bytes, PixelFormat::Rgba)?;

Compress

use libjpeg_turbo_rs::{compress, PixelFormat, Subsampling};

let jpeg = compress(&rgb_pixels, width, height, PixelFormat::Rgb, 85, Subsampling::S420)?;

Builder API

use libjpeg_turbo_rs::Encoder;

let jpeg = Encoder::new(&pixels, width, height, PixelFormat::Rgb)
    .quality(85)
    .subsampling(Subsampling::S420)
    .progressive(true)
    .optimize_huffman(true)
    .icc_profile(&icc_data)
    .finish()?;

Lossless Transform

use libjpeg_turbo_rs::{transform_jpeg, TransformOp, TransformOptions};

let rotated = transform_jpeg(&jpeg_bytes, TransformOp::Rot90, &TransformOptions::default())?;

Scanline-Level I/O

use libjpeg_turbo_rs::ScanlineDecoder;

let mut decoder = ScanlineDecoder::new(&jpeg_bytes)?;
while decoder.output_scanline() < decoder.output_height() {
    let row = decoder.read_scanlines(1)?;
    // process row...
}
let img = decoder.finish()?;

Features

Codec Support

Pixel Formats

Grayscale, RGB, BGR, RGBA, BGRA, ARGB, ABGR, RGBX, BGRX, XRGB, XBGR, CMYK, RGB565

Chroma Subsampling

4:4:4, 4:2:2, 4:2:0, 4:4:0, 4:1:1, 4:4:1

SIMD

Both platforms have comprehensive SIMD coverage across the encode/decode pipeline.

All SIMD routines have scalar fallbacks. SIMD is enabled by default via the simd feature flag.

Additional Features

• Scaled IDCT (1/2, 1/4, 1/8)
• Lossless spatial transforms (rotate, flip, transpose)
• DCT coefficient access (read_coefficients / write_coefficients)
• Metadata: JFIF, EXIF, ICC profile, Adobe APP14, comments
• YUV plane encode/decode (raw component data)
• Scanline-level streaming API
• Crop decoding (MCU-aligned)
• Color quantization with dithering
• Error recovery mode
• Custom Huffman/quantization tables
• Restart markers (DRI)
• Progress callbacks

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT License (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Acknowledgments

This software is based in part on the work of the Independent JPEG Group.

Algorithms and implementation techniques referenced from libjpeg-turbo (IJG License / Modified BSD License) and zune-jpeg.