OxiArc 0.2.0 Released — LZW Lands for TIFF and GIF, Now 10 Crates on crates.io

The COOLJAPAN compression layer just grew an image codec.

Today we released OxiArc 0.2.0 — pure Rust archive and compression, now with a full LZW implementation for TIFF and GIF and availability on crates.io.

No C. No Fortran. No zlib. No libzip. No libarchive. No 7-zip. No external shared libraries.
No FFI overhead. No build hell.
Just clean, memory-safe, blazing-fast archiving and compression that compiles to a single static binary (or WASM) and runs everywhere.

Why OxiArc 0.2.0 matters

Handling archives and compression has long meant leaning on heavy native libraries — zlib, libzip, libarchive, 7-zip — with all the baggage that brings:

• Complex build systems and dependency hell
• Security risks from large, aging C codebases
• Platform-specific binaries and vendor lock-in
• Difficulty in WASM, embedded, or no_std environments
• Inconsistent support for legacy formats like LZH and Shift_JIS (still widely used in Japan)

0.2.0 closes a real gap. LZW is the compression scheme behind GIF and TIFF, and until now a pure-Rust pipeline that touched raster images still had to pull in an outside codec for it. With oxiarc-lzw, that part of the image stack is now sovereign too — and the whole workspace is a cargo install away.

Technical Deep Dive: The New LZW Codec

OxiArc keeps its layered shape — a core layer, codec crates, a container layer, and a CLI — and 0.2.0 slots a new codec crate cleanly into the Codec Layer.

1. Core Layer (oxiarc-core)
   Shared Compressor/Decompressor traits, CRC-32/64/16 with slicing-by-8, and bitstream utilities. In 0.2.0, oxiarc-lzw now consumes oxiarc-core via workspace = true, tightening dependency management across the tree.

2. Codec Layer — now joined by oxiarc-lzw, a complete LZW implementation:

   • Both MSB-first and LSB-first bitstreams — the two orderings GIF and TIFF disagree on.
   • Variable bit width — 9–12 bits for TIFF, 2–12 bits for GIF.
   • Configurable TIFF/GIF modes, so you pick the dialect that matches your format.

3. Container Layer (oxiarc-archive)
   ZIP, TAR, GZIP, LZH, XZ, and friends — the 10-format container set carried forward from 0.1.0.

4. CLI Layer (oxiarc-cli)
   The unified oxiarc binary, now built and tested with newer tooling.

With LZW in place the workspace reaches 10 crates, and the comprehensive suite grows to 427 tests — all passing, with zero Clippy warnings under -D warnings, zero rustdoc warnings, and a clean security audit (0 vulnerabilities across 131 scanned dependencies).

Getting Started

0.2.0 is on crates.io. Install the CLI:

cargo install oxiarc-cli            # the `oxiarc` CLI

Or pull in just the crates you need as a library:

cargo add oxiarc-archive            # or oxiarc-deflate / oxiarc-lzw / ...

The library API is unchanged and ergonomic:

use oxiarc_deflate::{deflate, inflate};
use oxiarc_archive::ZipReader;
use std::fs::File;

let compressed = deflate(b"Hello, World!", 6)?;   // level 0-9
let decompressed = inflate(&compressed)?;

let file = File::open("archive.zip")?;
let mut zip = ZipReader::new(file)?;
for entry in zip.entries() {
    println!("{}: {} bytes", entry.name, entry.size);
}

What’s New in 0.2.0

• New crate: oxiarc-lzw — complete LZW compression for TIFF and GIF, with MSB-first and LSB-first bitstreams, variable bit width (9–12 bits for TIFF, 2–12 bits for GIF), and configurable TIFF/GIF modes. The workspace is now 10 crates.
• crates.io availability — cargo install oxiarc-cli and cargo add now work; no more build-from-source required.
• A much faster test suite — resource-intensive stress tests are now marked #[ignore], cutting the default cargo test runtime from 137s to 32s (76% faster). Run the heavy ones with cargo test -- --ignored.
• More documentation — new README guides for oxiarc-bzip2, oxiarc-lz4, oxiarc-lzw, and oxiarc-zstd.
• Dependency and workspace cleanup — bumps to clap 4.5.57, clap_complete 4.5.65, and criterion 0.8.2; improved workspace dependency management (oxiarc-lzw uses workspace = true for oxiarc-core); and version sync across all 10 crates.

Quality this release: zero Clippy warnings (-D warnings), zero rustdoc warnings, 100% test pass (427/427), and a clean security audit (0 vulnerabilities, 131 dependencies scanned).

Tips

Getting the most out of the new codec and the faster suite:

• Pick the right LZW dialect. Use the TIFF mode for TIFF data and the GIF mode for GIF — they differ in both bit-width range and defaults, and mismatching them produces garbage.
• Mind the bit order. GIF expects LSB-first packing while TIFF is MSB-first. oxiarc-lzw supports both; set the ordering to match the consumer.
• Run the stress tests on demand. The fast default suite skips the heavy cases; before a release, run cargo test -- --ignored to exercise them.
• Add only what you need. For an image pipeline, cargo add oxiarc-lzw pulls in the LZW codec without the rest of the archive stack.
• This is the codec GIF and TIFF actually use. If you were reaching for an image library mainly for its LZW path, oxiarc-lzw replaces that piece with a pure-Rust equivalent.

This is the foundation

OxiArc is the compression and archival backend other COOLJAPAN projects build on. It still depends on no sibling projects — just small, focused Rust crates — so siblings sit on top of it, not beside it.

With LZW in hand, OxiArc now covers the raster-image compression that NumRS2, PandRS, and SciRS2 pipelines run into — GIF and TIFF handling included — alongside the dataset compression and long-term storage they already lean on. It is the quiet data-packaging layer underneath the COOLJAPAN scientific stack.

Repository: https://github.com/cool-japan/oxiarc

Star the repo if you want high-performance archiving and compression without the traditional native toolchain headaches.

Pure Rust archiving and compression is here — fast, safe, and sovereign.

— KitaSan at COOLJAPAN OÜ February 6, 2026