Mozjpeg

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MozJPEG

https://github.com/mozilla/mozjpeg
MozJPEG is a JPEG image codec that improves compression efficiency achieving higher visual quality and smaller file sizes at the same time. It is compatible with the JPEG standard and most JPEG decoders.

This library aims to speed up loading times of webpages by achieving a reduction in file size and therefore transmission time through improvement of coding efficiency while retaining image quality. To achieve this, it uses more processing power for the encoding (asymmetry) while retaining full compatibility with the JPEG standard and requiring no changes on the decoder side.

The techniques MozJPEG uses to achieve high compression include optimising Huffman trees, using progressive coding to optimally split the spectrum of DCT coefficients into separate scans, and through the use of trellis quantisation. Additionally, the presets are aggressively tuned towards the minimisation of file sizes.

MozJPEG is a fork of libjpeg-turbo. MozJPEG is compatible with the libjpeg API and ABI. It is intended to be a drop-in replacement for libjpeg. MozJPEG is a strict superset of libjpeg-turbo's functionality. All MozJPEG's improvements can be disabled at run time, and in that case it behaves exactly like libjpeg-turbo.

Besides libjpeg-turbo, MozJPEG also builds upon jpegcrush, a Perl script by Loren Merritt.

An internet application of this tool is available at https://mozjpeg.com/.

Features

  • Progressive encoding with "jpegrescan" optimization. It can be applied to any JPEG file (with jpegtran) to losslessly reduce file size.
  • Trellis quantization. When converting other formats to JPEG it maximizes quality/filesize ratio.
  • Comes with new quantization table presets, e.g. tuned for high-resolution displays.
  • Fully compatible with all web browsers.
  • Can be seamlessly integrated into any program that uses the industry-standard libjpeg API. There's no need to write any MozJPEG-specific integration code.





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Zlib

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Panos Alevropoulos

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19 July 2021

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IJG

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Panos Alevropoulos

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19 July 2021

Verified by

Panos Alevropoulos

Verified on

19 July 2021




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