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This is not a replacement for JPEG as such
Google has unexpectedly introduced an improvement for the familiar JPEG format — Jpegli.
Jpegli is not a replacement for JPEG. This is a new JPEG encoding library that is designed to be faster, more efficient, and more visually pleasing than traditional JPEG.
Google identifies several important factors:
- Jpegli provides a fully compatible encoder and decoder following the original JPEG standard and its most traditional 8-bit formalism, as well as API/ABI compatibility with libjpeg-turbo and MozJPEG.
- When images are compressed or decompressed using Jpegli, the images will appear sharper and have fewer observable artifacts.
- Despite the improvement in image quality and compression density, Jpegli's encoding speed is comparable to traditional approaches such as libjpeg-turbo and MozJPEG. This means web developers can easily integrate Jpegli into their existing workflows without sacrificing coding performance or memory usage.
- Jpegli can be encoded using more than 10 bits per component. Traditional JPEG encoding solutions only offer 8-bit encoding per component, which results in visible banding artifacts in slow gradients. Jpegli's 10-bit and higher-bit encodings occur in the native 8-bit formalism, and the resulting images are fully compatible with 8-bit viewers. 10-bit dynamics is available as an API extension and requires changes to the application code to use it.
- Jpegli compresses images more efficiently than traditional JPEG codecs, saving bandwidth and storage space and speeding up web pages.
Jpegli uses a number of new techniques to reduce noise and improve image quality. These include adaptive quantization heuristics from the JPEG XL reference implementation, improved quantization matrix selection, accurate calculation of intermediate results, and the ability to use a more advanced color space.
According to Google's own tests, Jpegli can compress high-quality images 35% better than traditional JPEG codecs.