On Thursday, Google announced a new image format, called WebP, which the company claims will result in smaller file sizes for commonly shared small image files.
According to Google, photos and other images make up about 65 percent of all content accessed via the Web, and therefore all Web traffic. Those same files re-encoded with WebP will produce files that are, on average, 39 percent smaller than other formats, reducing the load on servers, ISPs including mobile carriers, and the Web browser clients themselves.
Today, image files are typically encoded via JPEG, a standard that was originally published in 1992. JPEG is a lossy standard, which means that some of the image fidelity is lost when an image is encoded or re-encoded. Other file formats, such as .PNG, use lossless compression, which maintains the original image data.
"To improve on the compression that JPEG provides, we used an image compressor based on the VP8 codec that Google open-sourced in May 2010," Richard Rabbat, a product manager for Google, wrote in a
blog post. "We applied the techniques from VP8 video intra frame coding to push the envelope in still image coding. We also adapted a very lightweight container based on RIFF."
That format has already met with some opposition, including, reportedly, Apple chief executive Steve
Google posted a
set of images encoded in the new format, although they're a bit of a hack; since no browser (including Google's Chrome) supports displaying WebP images, they have been re-encoded in a .PNG format. Google said it plans to add support for WebP in Webkit, as well as Chrome, together with support for alpha-layer transparencies.
Google has posted the conversion tool
here, and provided a statistical analysis of the new format
here, where the company compares WebP to JEPG2000 and JPEG, finding it especially useful on small image sizes. According to one commenter on Google's blog post, Google has limited the WebP maximum file size to 16383 x 16383.
