WebP, WebM

logo webP: http://code.google.com/speed/webp/images/webplogo.png



----------------------------Intro 
WebP is an image format for lossy compressed image files. The format was first announced in 2010 by google.
WebP est un format d'image annoncé par Google en 2010 (comme nouveau mais en fait ce n'est qu'un composant du VP8).

As a derivative of the video format VP8, it is a "sister project" to the multimedia format WebM.
Il exploite un algorithme de compression avec pertes prédictif utilisé pour les images clés du VP8 qui est le codec vidéo du format WebM. 
Pour les images telles les captures d'écran avec des grands aplats et des textes, un format de compression sans pertes comme le PNG est plus adapté.
----------------------------Compatibili: 
The Google Chrome Frame plug-in for Internet Explorer and Opera 11.10.
http://www.google.com/chromeframe

All WebM-compatible browsers may also display WebP via a javascript shim:

• see a demo: http://antimatter15.github.com/weppy/demo.html
  or http://antimatter15.com/wp/2010/10/weppy-javascript-shim-for-webp-on-chrome-6-and-firefox-4-0/
  WebP is actually a lightweight container for a single VP8 frame (whereas WebM is a container based off Matroska meant for video). WebM support exists already in Chrome, Firefox and Opera (not safari 5.0.5...), so all that's needed to render it is to do a little magic to convert the RIFF encoded WebP image into a EBML/Matroska encoded single frame WebM video, loading it in a video and replacing the .webp image with the video element.

Google has released a plug-in for Microsoft Windows that enables WebP support in Microsoft Office 2010:

http://code.google.com/intl/en/speed/webp/docs/webp_codec.html

Use this link Viewing WebP images on Windows

For mac , use graphic converter (safari downloads webP file).

WebP converter download

Convert your favorite collection from PNG and JPEG to WebP by downloading the precompiled cwebp conversion tool for Linux, Windows or Mac OS X.

Gmail and Picasa Web Albums (Google web applications) support WebP.
----------------------------Metadata 
The RIFF container leads to an overhead of only 20 bytes and can hold additional metadata.
Le fichier webp peut contenir jusqu'à 4 métadonnées supplémentaires (nom de l'auteur, titre de l'image, informations sur le droit d'auteur, commentaires).

----------------------------Bookmark 

FAQ: http://code.google.com/speed/webp/faq.html
home: http://code.google.com/speed/webp/

----------------------------Use
The Previews feature of Google Search currently uses WebP internally to reduce disk space.
----------------------------Criticism

1) size: 

WebP is bitstream-compatible with VP8 and uses 14 bits for width and height. 

The maximum file size for WebP is 16383x16383 pixels.

La taille maximale d'une image WebP est de 16 383 × 16 383 pixels, soit environ 260 mégapixels.
This seems very limited given 25+MP cameras these days—and increasing.

2) blur: 

http://x264dev.multimedia.cx/archives/541

3) google?

https://www.eff.org/deeplinks/2004/04/gmail-rough-guide-protecting-your-privacy

Faut-il craindre l'abus de position dès ce niveau?

4)...