WEBP - Google Web Picture files

What is a WEBP file

Created in 2010 by Google, the open standard WEBP image format allows users to save images in both lossy and lossless compression. Developers at Google claim the compression efficiency allows images to be compressed to sizes up to 34% smaller than JPEG and PNG images while retaining high quality. The theory is that with the technology used to create WEBP images (assuming high levels of adopting this as a standard), the internet as a whole can be sped up due to the decreased storage space required for WEBP images, allowing larger volumes of images to be viewed simultaneously throughout the world at higher speeds.

Lossy compression of WEBP files is accomplished by the process of prediction. This technique requires pixels to be predicted based on surrounding blocks. The difference between the prediction and the actual image is processed and encoded. The prediction is efficient enough to where many of the blocks of pixels contain zero difference from the actual image. This process allows smaller image file sizes. Lossless compression is obtained through using parts of the image which have already been analyzed to construct the remainder of the image — a similar process to the lossy compression. Currently, WEBP files support animation, ICC profiles, XMP metadata, and large images maxing out at 16384x16384 tiles.

Here's a small, but not exhaustive list of programs that can open WEBP documents:

  • Adobe Photoshop
  • Google Chrome
  • Picasa