Guetzli encoder: Efficient JPEG compressor for web page loading

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Google released Guetzli, a new addition to its emerging set of tools for the open source community. Guetzli is an encoder that permits  JPEG files to be compressed to the extent of 35 percent, producing much faster web page loading.

The meaning of the term "Guetzli," is "cookie" in Swiss German, grants users to create smaller JPEG images while retaining compatibility with existing Web browsers, image processing applications and the current JPEG standard, Robert Obryk and Jyrki Alakuijala, software engineers at Google Research Europe say in an online article.

It gives the result same as Google's Zopfli algorithm, that produces shorter PNG and gzip files with the need of a new file format. They stated.

The technique varies from RNN-based image compression, RAISR and WebP that needs ecosystem and client changes for compression at Internet scale.

Google initially launched the Zopfi compression algorithm in 2013 and two years later introduced Brotli that offered faster page loads and up to 26 percent higher compression ratios than Zopfi.

Microsoft announced support for Brotli in Edge last year, that would make it broadly inter-operable across major browsers, as the latest versions of Chrome and Firefox already supported Brotli.

The resolution quality of JPEG is directly collated to its multi-stage compression process, software engineers explained.

"Guetzli specifically targets the quantification stage in which the more visual quality loss is introduced, the smaller resulting file," they say.

 "Guetzli strikes a balance between minimal loss and file size by employing a search algorithm that tries to overcome the difference between psycho-visual modeling of JPEG's format and Guetzli's psycho-visual model."

The model proximate color perception and visual masking in a thorough manner than what can be accomplished through simpler color transforms and diverse cosine transforms.

As experimented with human raters, Obryk and Alakuijala stated that images produced by Guetzil were favored than images from libjpeg files, even after the latter files were of the same size or lightly bigger, making the slower compression a valuable accommodation.