image-compressor-rs

Fast Rust CLI and library for image compression and optimization using best-in-class encoders — compress JPEG, PNG, WebP, and AVIF images with mozjpeg, oxipng, libwebp, and ravif.

Features

• Superior compression using the same specialized engines as Facebook, Google, and Mozilla — not generic ImageMagick
• Batch image compression across entire directories with recursive support
• Four optimized encoders — mozjpeg (JPEG), oxipng (PNG), libwebp (WebP), ravif (AVIF)
• Lossy and lossless modes for WebP and AVIF output
• Resize images during compression with fit or exact modes (Lanczos3)
• Metadata stripping by default for smaller files (EXIF, ICC profiles)
• Progressive JPEG support for faster web loading
• Fully self-contained — no external tools like ImageMagick required

Format	Engine	Notes
JPEG	mozjpeg	~10% better compression than libjpeg
PNG	oxipng	Lossless PNG optimizer (like optipng, in pure Rust)
WebP	libwebp	Google's WebP encoder, lossy + lossless
AVIF	ravif (rav1e)	Best compression ratios available today

Installation

From source

git clone https://github.com/JohnDotOwl/image-compressor-rs.git
cd image-compressor-rs
cargo install --path .

Prerequisites

• Rust 1.85+ (edition 2024)
• nasm for mozjpeg SIMD optimizations: brew install nasm (macOS) or apt install nasm (Linux)

Usage

Compress a single image

# JPEG compression with mozjpeg
image-compressor-rs compress photo.jpg out.jpg --quality 80

# Convert + compress to WebP
image-compressor-rs compress photo.png out.webp --quality 85

# Lossless WebP
image-compressor-rs compress photo.png out.webp --lossless

# AVIF with custom speed
image-compressor-rs compress photo.jpg out.avif --quality 70 --avif-speed 2

# Resize + compress
image-compressor-rs compress photo.jpg out.jpg --quality 80 --resize 1920x1080

Batch compress a directory

# Convert all images to WebP
image-compressor-rs batch ./images/ ./compressed/ --to webp --quality 85

# Recursive with AVIF output
image-compressor-rs batch ./images/ ./compressed/ --to avif --recursive --quality 70

# Optimize PNGs in-place (lossless)
image-compressor-rs batch ./icons/ ./icons-opt/ --to png --png-level 4

Command reference

Flag	Description	Default
--quality <1-100>	Compression quality	85 (JPEG/WebP), 80 (AVIF)
--lossless	Lossless mode (WebP, AVIF)	false
--progressive	Progressive JPEG	false
--keep-metadata	Preserve EXIF/metadata	false (strip)
--resize <WxH>	Resize dimensions	none
--resize-mode <fit|exact>	Resize strategy	fit
--overwrite	Overwrite existing files	false
--png-level <1-6>	PNG optimization level	2
--avif-speed <1-10>	AVIF encoding speed (1=slow/best)	4
--to <FORMAT>	Target format for batch (jpg/png/webp/avif)	—
--recursive	Process subdirectories (batch only)	false

Output

Single file:

compressed photo.png → photo.jpg (2.4 MB → 420 KB, saved 82.9%)

Batch:

compressed image1.png → image1.webp (2.4 MB → 180 KB, saved 92.5%)
compressed image2.jpg → image2.webp (1.1 MB → 340 KB, saved 69.1%)
batch complete: compressed=15, failed=0, skipped=2, saved 18.4 MB (74.2%)

How It Works

Input File
    ↓
[Read file bytes + get original size]
    ↓
[Decode with image crate (auto-detect format)]
    ↓
[Resize if --resize specified] (Lanczos3 filter)
    ↓
[Determine output format from file extension]
    ↓
[Route to specialized encoder]
    ├── JPEG → mozjpeg (quality, progressive scanning)
    ├── PNG  → oxipng (optimization level, metadata stripping)
    ├── WebP → libwebp (quality, lossy/lossless)
    └── AVIF → ravif (quality, speed, lossy/lossless)
    ↓
[Write compressed bytes to output]
    ↓
[Print stats: original → compressed, savings %]

For PNG-to-PNG compression, the tool skips the decode/re-encode step and passes the raw bytes directly to oxipng for optimal lossless optimization.

Supported Input Formats

JPEG, PNG, WebP, GIF, BMP, TIFF — any format the image crate can decode.

Library Usage

Add to your Cargo.toml:

[dependencies]
image-compressor-rs = "0.1"

use image_compressor_rs::{compress_image_file, CompressOptions};
use std::path::Path;

let options = CompressOptions {
    quality: Some(80),
    progressive: true,
    ..CompressOptions::default()
};

let stats = compress_image_file(
    Path::new("input.jpg"),
    Path::new("output.jpg"),
    &options,
).unwrap();

println!("saved {:.1}%", stats.savings_percent);

Contributing

Contributions are welcome. To contribute:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/my-feature)
3. Commit your changes
4. Push to the branch and open a Pull Request

Please keep PRs focused and include tests where applicable.

License

MIT License. See LICENSE for details.