Naimated portable Network Graphics — Wikipedia
A wikipedia article, free l’encyclopéi.
Apng ( Animated Portable Network Graphics ) is an unofficial extension of the PNG format, an open digital image format.
The format Apng is specially designed to make graphics animations for the web. It is positioned in competition with the GIF (Graphics Interchange Format) image file format and more particularly what is commonly called animated GIF.
The PNG was created by the W3C to replace the GIF. In addition to the fact that the GIF used several computer patents (the last patent on the GIF expired the ), this format also had technical limitations: 256 colors, one of which can be transparent, no alpha channel.
The PNG working group then created the MNG (Multiple-Image Network Graphics) format allowing to obtain animations containing compressed fixed images in PNG or JPEG format in the spirit of the JNG format, managing 8 to 16 bits of levels of levels Transparencies and allowing several layers to manage and move an object in time rather than having several copies, as in the case of GIF or APNG today.
Several attempts to integrate the mozilla of MNG and JNG have been proposed; The former were accepted and integrated, but rejected a few years later, despite a high demand from the community [ first ] . This request will have already lasted 10 years from 1999 to 2009.
The APNG specification was made by Stuart Parment and Vladimir Vukicevic for the Mozilla Corporation in 2004.
Mozilla Firefox uses this format from its advanced version 3 of .
The PNG working group has officially rejected the APNG as an official extension . The reason for rejection is the same reason why the PNG format had no animation at the start: the PNG is a simple fixed image format. In addition, the Mime type of the apng should be different, which goes against the will of the inventors of the APNG: to have a format that still displays something with the navigators not supporting this format.
MNng is the official W3C format for animations. Mozilla Corporation has decided not to use the MNng format, this format being too heavy and the library not being mature enough [ 2 ] . The developers of Mozilla demanded a MNG/JNG manager of less than 5 KB, the developer of the graft therefore reduced the size of the MNG/JNG manager to 5 KB, but he was still rejected by the Mozilla Foundation without other arguments.
The advantage of APNG is the reduced size of the library [ 3 ] and its compatibility with old PNG implementations.
It consists of a patch for the PNG library which is not integrated into it, since it is not considered a format valid by its authors.
An APNG file is actually a valid PNG file. In this PNG image, the space for data extensions, which is provided by the original standard of the PNG, contains the following images in PNG format. A program using an old PNG library, only has to recover this additional data, to decode it and thus superimpose the images.
In an APNG file, the first image is a normal PNG, and can therefore be read by most PNG decoders. Most of the old PNG decoders will be able to display the first image.
The number of images per second as well as the following images are stored in additional space as specified in the original PNG format.
Software [ modifier | Modifier and code ]
- Apng assemble , a web-user allowing the assembly of APNG entertainment
- APNG Anime Maker, a small program allowing the creation of ANPG files.
- APNG Edit and Animat, two extensions by Mozilla Firefox 3, both allow to assemble images in order to create APNG animations.
- GIF Movie Gear 4, Shareware for Windows operating under Wine, allows you to create, edit and convert the APNG formats.
- Japng Edit, a small utility in Java allowing the creation and editing of APNG entertainment
- Konvertor, from version 4.02 ( )
- Ksquirrel, since version 0.7.2 ( )
- SVG2PNG, a program being developed therefore not entirely stable, allows you to convert SVG formats into PNG and animate them.
- XNVIEW, from version 1.92 ( )
- VirtualDub APNG Mod , a modification of virtualdub allowing to convert a .avi file to APNG animation.
[ modifier | Modifier and code ]
Related articles [ modifier | Modifier and code ]
external links [ modifier | Modifier and code ]
Recent Comments