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{{Short description|Digital image file format}}

factoids

bellard.org/bpg}}}}Better Portable Graphics (BPG) is a file format for coding digital images, which was created by programmer Fabrice Bellard in 2014. He has proposed it as a replacement for the JPEG image format as the more compression-efficient alternative in terms of image quality or file size.WEB,weblink BPG Image format, Fabrice Bellard, 2014, 2016-04-02, It is based on the intra-frame encoding of the High Efficiency Video Coding (HEVC) video compression standard. Tests on photographic images in July 2014 found that BPG produced smaller files for a given quality than JPEG, JPEG XR and WebP.The format has been designed to be portable and work in low memory environments, and used in portable handheld and IoT devices, where those properties are particularly important. Current research works on designing and developing more energy-efficient BPG hardware which can then be integrated in portable devices such as digital cameras.U. Albalawi, S. P. Mohanty and E. Kougianos, "Energy-Efficient Design of the Secure Better Portable Graphics Compression Architecture for Trusted Image Communication in the IoT", in Proceedings of the 15th IEEE Computer Society Annual Symposium on VLSI (ISVLSI), 2016, pp. 302--307.U. Albalawi, S. P. Mohanty, and E. Kougianos, “A Hardware Architecture for Better Portable Graphics (BPG) Compression Encoder”, in Proceedings of the 1st IEEE International Symposium on Nanoelectronic and Information Systems, 2015, pp. 291-296.While there is no built-in native support for BPG in any mainstream browsers, websites can still deliver BPG images to all browsers by including a JavaScript library written by Bellard. Others followed Bellards idea and created the AVIF image format based on the AV1 video codec, which is patent free and therefore got implemented in browsers.

Origin in HEVC

{{further|High Efficiency Video Coding#Version 2 profiles|High Efficiency Video Coding#Main Still Picture}}HEVC has several profiles defined for extending its intra-frame encoding to still images at various bit depths and color formats, including "Main Still Picture," "Main 4:4:4 Still Picture," and "Main 4:4:4 16 Still Picture profiles." BPG is a wrapper for the "Main 4:4:4 16 Still Picture" profile up to 14 bits per sample.

Specifications

BPG's container format is intended to be more suited to a generic image format than the raw bitstream format used in HEVC (which is otherwise ordinarily used within some other wrapper format, such as the .mp4 file format).WEB,weblink BPG specification, 17 November 2017, BPG supports the color formats known as (chroma subsampling|4:4:4), (4:2:2), and (4:2:0). Support for a separately coded extra channel is also included for an alpha channel or the fourth channel of a CMYK image. Metadata support is included for Exif, ICC profiles, and XMP.Color space support is included for YCbCr with ITU-R BT.601, BT.709, and BT.2020 (non-constant luminance) definitions, YCgCo, RGB, CMYK, and grayscale.Support for HEVC's lossy and lossless data compression is included. BPG supports animation.

Patents

According to Bellard's site BPG may be covered by some of the patents on HEVC, but any device licensed to support HEVC will also be covered for BPG. Patent issues may prevent JPEG replacement by BPG despite BPG's better technical performance.WEB,weblink BPG, a still-image format from video compression, LWN.net,

Other proposed JPEG replacements

Several other image formats have also been proposed as JPEG replacements, including:WEB,weblinkweblink" title="web.archive.org/web/20160928024026weblink">weblink dead, 2016-09-28, Lossy Compressed Image Formats Study, Mozilla Corporation, WEB,weblink BPG Image Comparison, 2015-02-10,

• AVIF, image format based on the AV1 video codecWEB,weblink AV1 Still Image File Format (AVIF), aomediacodec.github.io, en, 2018-04-15,
• FLIF
• HEIF, another container for HEVC intra-frames
• JPEG 2000
• JPEG XL
• JPEG XR
• WebP, image format based on VP8

References

{{Reflist}}

External links

• {{Official website|bellard.org/bpg}}
• BPG – image comparison

{{Graphics file formats}}{{Compression formats}}