JPEG XL
| JPEG XL | |
|---|---|
| Filename extension |
.jxl |
| Internet media type |
image/jxl |
| Uniform Type Identifier (UTI) | public.jpeg-xl |
| Magic number | FF 0A or 00 00 00 0C 4A 58 4C 20 0D 0A 87 0A |
| Developed by | |
| Initial release | 13 October 2021 |
| Type of format | Lossy/lossless bitmap image format |
| Extended from | |
| Standard | ISO/IEC 18181 |
| Open format? | Yes |
| Website |
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The JPEG XL Image Coding System (JPEG XL, sometimes shortened to JXL) is an image format that supports both lossy and lossless compression. It was developed by the Joint Photographic Experts Group (JPEG), Google and Cloudinary. It is a free and open standard defined by ISO/IEC 18181. The standard consists of four parts that cover the Core coding system, File format, Conformance testing, and Reference software, respectively.
JPEG XL features a lossy compression mode called VarDCT built on block-based transform coding, which is similar to — but significantly improves and expands upon — the compression method of JPEG, and a modular mode that allows different features of the format to be combined in a "modular" way. Modular mode can be used either for lossless image compression, similar to PNG, or as a means to achieve lossy compression in a different way from VarDCT.
The name refers to the design committee (JPEG), the X designates the series of its image coding standards published since 2000 (JPEG XT/XR/XS), and L stands for "long-term", highlighting the intent to create a future-proof, long-lived format to succeed JPEG/JFIF.
The main authors of the specification are Jyrki Alakuijala, Jon Sneyers, Zoltan Szabadka, and Luca Versari. Other collaborators are Sami Boukortt, Alex Deymo, Moritz Firsching, Thomas Fischbacher, Eugene Kliuchnikov, Robert Obryk, Alexander Rhatushnyak, Lode Vandevenne, and Jan Wassenberg.