WebP, a new image format for the Web than Google

As part of Google's initiative to make the web faster, over the last few months we have released a number of tools to help site owners to accelerate their Web site. We launched Page Speed ​​Firefox extension to evaluate the performance of web pages and to get advice on how to improve them, we introduce the Speed ​​Tracer Chrome extensions to help identify and fix performance issues in web applications, and we release the closure of a set of tools to help build web applications rich with optimized JavaScript code. Although the tool has been very successful in helping developers optimize their sites, as we have evaluated our progress, we continue to see a web page component is consistently responsible for most of the latency on the web pages: images.

Most common image formats on the web today was founded more than a decade ago and is based on technology from around that time. Some engineers at Google decided to find out whether there is a way to further compress JPEG pictures lossy like to make them load faster, while maintaining the quality and resolution. As part of this effort, we released a developer preview of new image formats, WebP, which promises to significantly reduce the byte size of the photo on the web, allowing web sites to load faster than before.
Images and photographs make up about 65% of the bytes transmitted per web page today. They can significantly slow the user's web experience, especially in bandwidth-limited networks such as mobile networks. Pictures on the web mainly consists of a lossy format like JPEG, and to a lesser extent lossless formats like PNG and GIF. Our team focuses on improving lossy image compression, which is a larger percentage of the image on the web today.

To fix that provides JPEG compression, we use an image compressor based on VP8 codec that Google's open-source in May 2010.Kami apply the technique of intra coding VP8 video frame to push the envelope in still image coding. We also adapt a container which is a light based on the RIFF. While this container format donate a minimum of overhead is only 20 bytes per image, it can be developed to allow authors to store meta-data that they want to save.

While the benefits of VP8-based image format is clear in theory, we must examine them in the real world. In order to measure the effectiveness of our efforts, we randomly took approximately 1,000,000 images from the web (mostly JPEG and a PNG and GIF) and re-encode them to WebP understandable without sacrificing visual quality. This resulted in 39% reduction in the average size of the file. We hope that the developer will achieve better in the practice of file size reduction with WebP when starting from a compressed image.

To help you assess's performance WebP with other formats, we have shared the choice of open source and classic images along with a file size so you can visually compare them on this site. We also released a conversion tool that allows you to convert images into formats WebP. We look forward to working with the browser and the web developer community in the spec WebP and about how to add native support for WebP. While WebP pictures can not be seen until the browser supports this format, we are developing a patch for WebKit to provide native support for WebP in the launch of Google Chrome. We plan to add support for transparent layers, also known as the alpha channel in future updates.

We are very excited to hear feedback from the developer community on our discussion group, so the download conversion tool, try it on set your favorite images, and let us know what you think.

source: http://blog.chromium.org/2010/09/webp-new-image-format-for-web.html