# jbig2dec

> free JBIG2 decoder library

**Wikidata**: [Q103732812](https://www.wikidata.org/wiki/Q103732812)  
**Source**: https://4ort.xyz/entity/jbig2dec

## Summary
jbig2dec is a free software library implemented in C designed to decode JBIG2 image files. Developed by Artifex Software, it is distributed under the GNU Affero General Public License (version 3.0 or later). The library is classified as both a decoder and a free software utility, with its latest stable release (version 0.20) published in September 2023.

## Key Facts
- **Developer:** Artifex Software.
- **Latest Stable Version:** 0.20 (released September 14, 2023).
- **License:** GNU Affero General Public License, version 3.0 or later.
- **Software Type:** Free software, software library, and decoder.
- **Primary Function:** Decodes files in the JBIG2 format (readable file format).
- **Programming Language:** C (identified as Wikidata Q15777).
- **Official Website:** https://jbig2dec.com/
- **Source Code Repository:** Hosted at git.ghostscript.com with a mirror on GitHub.
- **Copyright Status:** Copyrighted.

## FAQs
### Q: What is jbig2dec used for?
A: jbig2dec is a software library used to decode and process images compressed using the JBIG2 standard. It provides the necessary tools for software applications to read and render these specific image files.

### Q: Who maintains jbig2dec?
A: The library is developed and maintained by Artifex Software. The project also utilizes an issue tracker located at bugs.ghostscript.com.

### Q: Under what license is jbig2dec distributed?
A: The software is distributed under the GNU Affero General Public License, version 3.0 or later. This ensures it remains free software, allowing users to run, study, and modify the code.

### Q: Where can the source code be found?
A: The source code is available via a Git repository at git.ghostscript.com and is mirrored on GitHub under ArtifexSoftware.

## Why It Matters
jbig2dec serves a critical role in the document imaging and open-source software ecosystems by providing a standardized, free implementation of the JBIG2 decoder. JBIG2 (Joint Bi-level Image Experts Group 2) is a compression standard primarily used for bi-level images (such as black-and-white scanned documents), offering significantly better compression ratios than earlier formats. Without a reliable decoder like jbig2dec, software suites would struggle to render high-efficiency scanned documents found in modern PDFs and digital archives.

As a free software library licensed under the AGPLv3+, it enables developers to integrate high-fidelity image decoding into their applications without proprietary restrictions. Its development by Artifex Software—the same entity behind Ghostscript—ensures that it is well-maintained and compatible with major open-source printing and document rendering pipelines. The project's active maintenance is evidenced by its recent stable release in 2023, highlighting its continued relevance in modern software infrastructure.

## Notable For
- Being a **free software** implementation of a specialized compression standard (JBIG2).
- Development by **Artifex Software**, a prominent entity in the document processing and printing software industry.
- Distribution under the **AGPLv3+**, a copyleft license that guarantees user freedoms for modification and distribution.
- Integration into the broader **Ghostscript ecosystem**, inferred from its repository hosting and issue tracker domain.
- Availability across various package managers, evidenced by listings in **MacPorts** and **Repology**.

## Body

### Development and Release History
jbig2dec is actively maintained by Artifex Software. The project tracks its versions and releases via GitHub and its official website.
- **Stable Release:** The most recent stable version is **0.20**, which was released on **September 14, 2023**.
- **Release Data:** This version was cataloged in the project's release notes (cited as "Release 0.20") and verified on October 14, 2023.

### Technical Specifications
The library is built to handle the specific requirements of the JBIG2 standard.
- **Implementation:** It is written in the **C** programming language (Wikidata ID Q15777).
- **Functionality:** It functions strictly as a decoder for the JBIG2 file format.
- **Platforms:** The software is available through MacPorts (listed as `jbig2dec`) and is tracked by Repology.

### Repository and Resources
The project maintains a primary code repository and utilizes mirrors for public access.
- **Primary Repository:** `git://git.ghostscript.com/jbig2dec.git`
- **Web Interface:** `http://git.ghostscript.com/?p=jbig2dec.git` (Preferred Gitweb interface).
- **GitHub Mirror:** `https://github.com/ArtifexSoftware/jbig2dec` (Designated as a mirror storage).
- **Bug Tracking:** Issues are managed via `https://bugs.ghostscript.com`.
- **Project Listings:** Historic or alternative listings exist on SourceForge as `jbig2dec`.

## References

1. [Source](https://github.com/ArtifexSoftware/jbig2dec)
2. [Release 0.20. 2023](https://github.com/ArtifexSoftware/jbig2dec/releases/tag/0.20)