WebP

from Wikipedia, the free encyclopedia
WebP
WebP logo
FFMpeg libwebp.png

File extension : .webp
Magic number : WEBP
Developed by: Google , On2
Initial release: 2010
Type: Graphic format
Contained in: REEF
Extended by: VP8
Website : developers.google.com/speed/webp

WebP is a graphics format for lossy or losslessly compressed static or animated images. As a further derivative of the VP8 video codec released in 2010, it is a sister project of the WebM video format .

pronunciation

According to the filename extensions directory Dot What? WebP is pronounced like "weppy" in English.

features

It offers 4: 2: 0 color subsampling (only) . It supports images with side lengths of up to 16,383 (14 bits: 2 14 −1) pixels.

With very high compression, WebP achieves more image quality per data volume than JPEG . It works particularly effectively at the compression of low-detail, uniform parts of the image.

On October 3, 2011, WebP support for animations, ICC profiles , XMP metadata and tiling (“tiling”; large, composite images made up of a maximum of 16384 × 16384 parts) was introduced. On November 18, 2011, experimental lossless compression and support for transparency ( alpha channel ) were introduced in both lossy and lossless modes. Support was activated by default with the introduction of libwebp 0.2.0 (August 16, 2012).

The software for editing and displaying WebP is published under the BSD license .

technology

The format is developed by Google on the basis of the intra-frame coding of the VP8 video codec and the RIFF container format and is bitstream compatible with VP8. As such, it is a block-based (4 × 4 pixel block size) transformation method with eight bit color depth and a brightness-chromaticity color model with color subsampling in the ratio 1: 2 ( YCbCr 4: 2: 0). It uses a comparatively advanced entropy coding - a kind of binary arithmetic coding (similar to CABAC ). The mandatory RIFF container leads to an overhead of only 20 bytes without any further content and can be used for additional metadata .

The free reference implementation consists of a conversion software in the form of a command line program for Linux (cwebp) and a program library for decoding (the same as for WebM).

use

An example for WebP

The format is intended to serve as a new open standard for lossy compressed real-color graphics on the web and is thus placed as a direct competitor to the older JPEG , which is supposed to enable significantly smaller files with comparable quality. In March 2017, Google presented a new open source JPEG encoder called “Guetzli”.

Supporting web browsers

Google's own web browser Chrome will be the first browser to support the format from October 2010; Opera from version March 2011. Since January 2019 Firefox from version 65 supports WebP.

The Google developers finally added WebP support as part of the WebKit rendering engine so that all WebKit-based browsers, such as Safari , can also use the format. Safari supports WebP from version 14.

Edge supports WebP from version 1809 (RS5) of Windows 10.

Since April 2011, Opera has been using the standard format for images that are compressed and transmitted via Opera's proxy server for the “Opera Turbo” function.

Konqueror , KDE's web browser , supports WebP from KDE version 4.11. Since the image formats are implemented in KDE as reusable components, any graphics program under KDE can use WebP (e.g. KolourPaint , Gwenview , Krita , Calligra , ...)

Supporting graphics programs

ACDSee , Affinity Photo and Pixelmator support WebP without a plug-in. The current versions of GIMP , IrfanView , Paint.NET and XnView support both reading and writing of WebP when the necessary plug-ins are installed. Even Photoshop supports WebP via a plugin.

Use in messengers

Since May 19, 2015, users of the Messenger Telegram can create virtual collections of stickers and publish them to friends. These are based on WebP files with up to 512 × 512 pixels, but still link an emoji with them. WhatsApp has also supported stickers with this format since the end of 2018 . Also signal (Messenger) supports WebP as the format for stickers.

criticism

The format presented when it was first published and its (reference) implementation are still remarkably unusable. Jason Garrett-Glaser, a developer of the x264 encoder, made several criticisms of WebP. WebP only supports 4: 2: 0 color subsampling. The 4: 2: 2 and 4: 4: 4 supported by the JPEG format were missing. The quality of comparison images in WebP format is apparently worse and more blurred than those in JPEG format despite the superior format with the same file size, because the encoder does not use any perceptual psychological optimizations. Since then, Pascal Massimino, the developer of the cwebp encoder, has improved it and corrected most of the bugs noted, whereby the above. Points are largely obsolete. Jason Garrett-Glaser correctly points out that the H.264 “intra-frame” algorithm delivers better results than VP8, but, unlike VP8, is subject to patents.

Comparative tests in 2010 showed a tendency for medium to high quality settings to show inferior compression results and difficulties with detailed image material.

Mozilla declined WebP support for its products until March 2013 because the format does not yet offer a clear advantage over JPEG.

In December 2016, Google's own study then showed an advantage of 25–34 percent in compression compared to JPEG with comparable structural similarity (SSIM).

Others

According to statistics from W3Techs, the use of 0.3% of the websites examined (as of July 2020) is very low.

In 2017, another new format from Google called PIK appeared on GitHub . Apparently it can compress a lot more, although it is called unofficial, but it should be included in the development of the new JPEG XL. In addition, a new format called HEIF was introduced for new Apple devices , which also offers high compression rates, but is also not yet fully supported. As a variant of this, one must consider the new AVIF format , which is specified by the Alliance for Open Media and is based on the AV1 video codec.

See also

Web links

Individual evidence

  1. ↑ Stephen Shankland: Google offers JPEG alternative for faster Web. Deep Tech - CNET News, September 30, 2010; accessed October 1, 2010 .
  2. ↑ Golem.de: Google: WebP should replace Jpeg - Golem.de. October 1, 2010, accessed October 1, 2010 .
  3. ↑ Nils Baer: Google presents a new graphic format: 'WebP' should become the JPEG killer. Basic Thinking, October 1, 2010, accessed March 2, 2011 .
  4. ↑ .WEBP File Extension - Google Image File on dotwhat.net, accessed December 31, 2019.
  5. ↑ a b kidjan: Comparison: WebP, JPEG and JPEG XR. October 10, 2010, accessed May 26, 2011 .
  6. ↑ WebP-Mux (RIFF based container) framework
  7. ↑ WebP v0.2.0 decoder and encoder source tree ( Memento from July 1, 2013 in the Internet Archive )
  8. ^ Google Developers Blog: Lossless and Transparency Modes in WebP
  9. ↑ RFC 6386 VP8 Data Format and Decoding Guide
  10. ↑ Daniel Berger: Google's biscuit encoder shrinks JPEG images by a third. In: heise online. Heise Zeitschriften Verlag, March 17, 2017, accessed on February 19, 2019 .
  11. ^ Nicola D'Agostino: Chromium supporta le immagini WebP! (No longer available online.) In: Mondo Chrome. October 29, 2010, archived from the original on November 9, 2010 ; Retrieved November 22, 2010 (Italian).
  12. ↑ Ruari Ødegaard : CSS gradients, WebP, and Declarative UI. In: Opera Desktop Team . March 15, 2011, archived from the original on March 17, 2011 ; accessed on March 15, 2011 (English).
  13. ↑ Firefox 65.0, See All New Features, Updates and Fixes. Retrieved January 30, 2019 .
  14. ↑ Apple Developer Documentation. Retrieved August 8, 2020 .
  15. ↑ What's new in Microsoft Edge in the Windows 10 October 2018 Update - Microsoft Edge Dev BlogMicrosoft Edge Dev Blog. Retrieved November 12, 2018 (American English).
  16. ^ Audun Mathias Øygard: On a horse? Opera Turbo to the rescue! April 11, 2011, archived from the original on April 14, 2011 ; accessed on May 26, 2011 (English).
  17. ^ Frank M. Palinkas, Technical Writer, Opera Software ASA : Opera 11.10 for Windows changelog. In: Opera Desktop Team . April 12, 2011, accessed April 14, 2011 .
  18. ↑ KDE QuickGit :: kde-runtime.git / commit. (No longer available online.) Formerly in the original ; Retrieved November 18, 2013 .  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Dead Link / quickgit.kde.org  
  19. ↑ GIMP - GIMP 2.9.2 Released. In: www.gimp.org. Retrieved September 29, 2016 .
  20. ↑ Create WebP graphics with Photoshop plug-in. Retrieved on July 20, 2020 (German).
  21. ↑ webmproject / WebPShop. WebM Project, July 20, 2020, accessed July 20, 2020 .
  22. ↑ Custom sticker sets. In: Telegram blog. May 19, 2015, accessed June 6, 2015 .
  23. ^ Telegram Stickers for Everyone. In: Telegraph. October 28, 2018, accessed November 29, 2018 .
  24. ^ Jason Garrett-Glaser: Diary Of An x264 Developer »H.264 and VP8 for still image coding: WebP? (No longer available online.) September 30, 2010, archived from the original on November 27, 2010 ; Retrieved October 1, 2010 .
  25. ↑ Jason Garrett-Glaser: H.264 and VP8 for still image coding: WebP? (No longer available online.) In: Diary Of An x264 Developer. September 30, 2010, archived from the original on March 19, 2015 ; accessed on November 22, 2010 (English).
  26. ↑ bugzilla.mozilla.org
  27. ↑ Oliver Diedrich: Google and Mozilla quarrel over WebP. In: heise open. Heise Zeitschriften Verlag, May 25, 2011, accessed on May 26, 2011 .
  28. ↑ developers.google.com
  29. ↑ Usage Statistics of Image File Formats for Websites, July 2020. w3techs, accessed July 11, 2020 .
  30. ↑ Stephen Hall: Google is working on a new lossy image format for the web called 'Pik'. In: 9to5Google. July 24, 2017. Retrieved August 28, 2018 .
  31. ↑ google / pik. Accessed August 28, 2018 .
  32. ↑ How JPEG XL Compares to Other Image Codecs. Retrieved July 11, 2020 .
  33. ↑ moinmoin: AVIF file format is supported by Windows 10 1903. December 27, 2018, accessed December 29, 2018 .