slimg-0.4.0 is not a library.

slimg

A fast image optimization CLI. Convert, compress, resize, crop, and extend images using modern codecs.

Supported Formats

Format	Decode	Encode	Notes
JPEG	Yes	Yes	MozJPEG encoder for superior compression
PNG	Yes	Yes	OxiPNG optimizer with Zopfli compression
WebP	Yes	Yes	Lossy encoding via libwebp
AVIF	Yes	Yes	ravif encoder; dav1d decoder (statically linked)
QOI	Yes	Yes	Lossless, fast encode/decode
JPEG XL	Yes	No	Decode-only (GPL license restriction)

Installation

Cargo (crates.io)

cargo install slimg

Homebrew (macOS / Linux)

brew install clroot/tap/slimg

Pre-built binaries

Download from GitHub Releases:

Platform	File
macOS (Apple Silicon)	`slimg-aarch64-apple-darwin.tar.xz`
macOS (Intel)	`slimg-x86_64-apple-darwin.tar.xz`
Linux (x86_64)	`slimg-x86_64-unknown-linux-gnu.tar.xz`
Linux (ARM64)	`slimg-aarch64-unknown-linux-gnu.tar.xz`
Windows (x86_64)	`slimg-x86_64-pc-windows-msvc.zip`

From source

git clone https://github.com/clroot/slimg.git
cd slimg
cargo install --path cli

Build requirements

Rust 1.85+ (edition 2024)
C compiler (cc)
nasm (for MozJPEG / rav1e assembly optimizations)
meson + ninja (for building dav1d AVIF decoder from source)
Set SYSTEM_DEPS_DAV1D_BUILD_INTERNAL=always to build dav1d from source

Usage

For the full usage guide, see docs/usage.md.

# Convert format
slimg convert photo.jpg --format webp

# Optimize (re-encode in same format)
slimg optimize photo.jpg --quality 70

# Resize
slimg resize photo.jpg --width 800

# Crop by coordinates
slimg crop photo.jpg --region 100,50,800,600

# Crop to aspect ratio (center-anchored)
slimg crop photo.jpg --aspect 16:9

# Extend to square with padding
slimg extend photo.jpg --aspect 1:1

# Extend with transparent background
slimg extend photo.png --aspect 1:1 --transparent

# Batch processing with format conversion
slimg convert ./images --format webp --output ./output --recursive --jobs 4

Benchmarks

See docs/benchmarks.md for detailed performance measurements across all codecs and pipeline operations.

Language Bindings

Language	Package	Platforms
Kotlin/JVM	`io.clroot.slimg:slimg-kotlin`	macOS, Linux, Windows
Python	`slimg`	macOS, Linux, Windows

Library

The core functionality is available as a library crate (slimg-core):

use slimg_core::*;

// Decode an image file
let (image, format) = decode_file(Path::new("photo.jpg"))?;

// Convert to WebP
let result = convert(&image, &PipelineOptions {
    format: Format::WebP,
    quality: 80,
    resize: None,
    crop: None,
    extend: None,
    fill_color: None,
})?;

// Save the result
result.save(Path::new("photo.webp"))?;

License

MIT

slimg 0.4.0