Google launches WebP, the new JPEG

Google has announced a competitor to the JPEG image file format, which it promises will "significantly" reduce the size of image files and speed up the web.

Images are reckoned to account for around 65 per cent of all data on the web - so squeezing down file sizes could enable web pages to load much more quickly, even using existing connection bandwidths.It will also help to make the most of existing storage capacity.

"Images and photos... can significantly slow down a user's web experience, especially on bandwidth-constrained networks such as a mobile network," explained product manager Richard Rabbat on Google's Chromium blog.

"In order to gauge the effectiveness of our efforts, we randomly picked about 1,000,000 images from the web (mostly JPEGs and some PNGs and GIFs) and re-encoded them to WebP without perceptibly compromising visual quality. This resulted in an average 39 per cent reduction in file size," said Rabbat.

Rabbat said that he expected developers to achieve an even greater saving in file size when starting from uncompressed source files.

The technology behind WebP comes from video compression specialist On2, which Google acquired last year. On2 is the company behind video codec WebM, designed as a competitor to H.264.

WebP is based on the same VP8 compression as WebM, but wraps it in a container based on the RIFF image standard. The savings Google is boasting about are achieved by using predictive compression.

With potential file size savings of 40 per cent or more, the technology sounds impressive - but even a company with Google's might will have its work cut out getting the format adopted as a universal standard.

The first nut to crack will be getting native support for the file format built into all major web browsers - no easy feat, with the spectre of patent licensing hanging over the format. The search giant has hinted at developing scripts that replace JPEGs with WebP images on the fly, but it seems unlikely such a workaround will catch on.

For the moment, those looking for native WebP support will have to wait for an upcoming release of Google's Chrome browser.

You can try the file format out for yourself using Google's open-source conversion tool, available to download here.