Google released a developer preview of a new image format “WebP,” that promises to significantly reduce the byte size of photos on the web, allowing web sites to load faster than before. “For assessing WebP’s performance with other formats, we’ve shared a selection of open-source and classic images along with file sizes to compare them. Also released a conversion tool to help you convert images to WebP. To make WebP images viewable in browsers, we’re developing a patch for WebKit to provide native support for WebP in upcoming Google Chrome,” stated Google.
“To improve on compression that JPEG provides, we used an image compressor based on VP8 codec. We applied the techniques from VP8 video intra frame coding to push the envelope in still image coding. We also adapted very lightweight container based on RIFF. While this container format contributes a minimal overhead of only 20 bytes per image, it’s extensible to allow authors to save meta-data they would like to store.
While benefits of VP8 based image format were clear in theory, to gauge the effectiveness in real world, we randomly picked about 1,000,000 “JPEGs, PNGs and GIFs images from the web and re-encoded them to WebP without perceptibly compromising visual quality. This resulted in an average 39% reduction in file size,” explained Google.