APNG hides the subsequent frames in PNG ancillary chunks in such a way that APNG-unaware applications would ignore them, but there are otherwise no changes to the format to allow software to distinguish between animated and non-animated images. In particular, PNG was conceived to be a single-image format. In May 2003, Mozilla had scrapped support for MNG animations, which provides a superset of APNG functionality, citing concerns about the large file size required for the expansive MNG decoder library (300 KB) the APNG decoder, built on the back of the PNG decoder, was a much smaller component.Īmong users and maintainers of the PNG and MNG formats, APNG had a lukewarm reception. The APNG specification was created in 2004 by Stuart Parmenter and Vladimir Vukićević of the Mozilla Corporation to allow for storing the animations needed for interfaces such as throbbers.

History An APNG of an MRI scan of a human head In a comparison made between GIF, APNG and lossless WebP, APNG had the lowest file size. APNG's advantage was the smaller library size and compatibility with older PNG implementations. APNG competed with Multiple-image Network Graphics (MNG), a comprehensive format for bitmapped animations which was created by the same team as PNG and is obsolete. The frame speed data and extra animation frames are stored in extra chunks (as provided for by the original PNG specification). The first frame of an APNG file is stored as a normal PNG stream, so most standard PNG decoders are able to display the first frame of an APNG file. It also retains backward compatibility with non-animated PNG files. Image/, image/apng, image/pngĪnimated Portable Network Graphics ( APNG) is a file format which extends the Portable Network Graphics (PNG) specification to permit animated images that work similarly to animated GIF files, while supporting 24-bit images and 8-bit transparency not available for GIFs.

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