WebP is a new image format announced by Google last week which aims at making the web faster by providing the tools to use high-quality, yet lightweight, images. While preserving quality and resolution, Google’s engineers figured out a way to compress images so to make them even smaller than usual .JPEG files. About the technical details:
WebP uses predictive coding to encode an image, the same methodology used by the VP8 video codec to compress keyframes in videos. Predictive coding uses the values in neighboring blocks of pixels to predict the values in a block, and then encodes only the difference (residual) between the actual values and the prediction. The residuals typically contain many zero values, which can be compressed much more effectively. The residuals are then transformed, quantized and entropy-coded as usual. WebP also uses variable block sizes.
Being a new file format, it’s not officially supported in browsers yet. Maybe it’ll be very soon, but right now it’s just a cool developer preview that shows what it’s possible to do with Google’s technology. Here’s how you can enable WebP in your Mac browser right now. Read more