Better Portable Graphics (BPG) is a

file format A file format is a Computer standard, standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary format, pr ...

for coding

digital images A digital image is an image composed of picture elements, also known as pixels, each with '' finite'', '' discrete quantities'' of numeric representation for its intensity or gray level that is an output from its two-dimensional functions f ...

, which was created by programmer Fabrice Bellard in 2014. He has proposed it as a replacement for the

JPEG JPEG ( , short for Joint Photographic Experts Group and sometimes retroactively referred to as JPEG 1) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degr ...

image format as the more compression-efficient alternative in terms of image quality or file size. It is based on the intra-frame encoding of the

High Efficiency Video Coding High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In compa ...

(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 WebP is a raster graphics file format developed by Google intended as a replacement for JPEG, PNG, and GIF file formats. It supports both lossy and lossless compression, as well as animation and alpha transparency. Google announced the 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. In 2015 research was working on designing and developing more energy-efficient BPG hardware which could potentially then be integrated in portable devices such as digital cameras. 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 JavaScript (), often abbreviated as JS, is a programming language and core technology of the World Wide Web, alongside HTML and CSS. Ninety-nine percent of websites use JavaScript on the client side for webpage behavior. Web browsers have ...

library written by Bellard. Others followed Bellard's 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

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 A container format (informally, sometimes called a wrapper) or metafile is a file format that allows multiple data streams to be embedded into a single file, usually along with metadata for identifying and further detailing those streams. Nota ...

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). BPG supports the color formats known as 4:4:4, 4:2:2, and 4:2:0. Support for a separately coded extra channel is also included for an

alpha channel In computer graphics, alpha compositing or alpha blending is the process of combining one image with a background to create the appearance of partial or full transparency. It is often useful to render picture elements (pixels) in separate pass ...

or the fourth channel of a

CMYK The CMYK color model (also known as process color, or four color) is a subtractive color model, based on the CMY color model, used in color printing, and is also used to describe the printing process itself. The abbreviation ''CMYK'' refers ...

image. Metadata support is included for

Exif Exchangeable image file format (officially Exif, according to JEIDA/JEITA/CIPA specifications) is a standard that specifies formats for images, sound, and ancillary tags used by digital cameras (including smartphones), scanners and other system ...

ICC profile In color management, an ICC profile is a set of data that characterizes a color input or output device, or a color space, according to standards promulgated by the International Color Consortium (ICC). Profiles describe the color attributes o ...

s, and XMP. Color space support is included for

YCbCr YCbCr, Y′CbCr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in digital video and digital photography, photography systems. Like YPbPr, YPBPR, it is based on RGB primaries; the two ...

with ITU-R BT.601, BT.709, and BT.2020 (non-constant luminance) definitions, YCgCo, RGB,

, and grayscale. Support for HEVC's

lossy In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size ...

and

lossless Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits statisti ...

data compression is included. BPG supports animation.

Patents

According to Bellard's site BPG may be covered by some of the

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling discl ...

s 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.

Other proposed JPEG replacements

Several other image formats have also been proposed as JPEG replacements, including: * AVIF, image format based on the AV1 video codec * FLIF * HEIF, another container for HEVC intra-frames *

JPEG 2000 JPEG 2000 (JP2) is an image compression standard and coding system. It was developed from 1997 to 2000 by a Joint Photographic Experts Group committee chaired by Touradj Ebrahimi (later the JPEG president), with the intention of superseding their ...

JPEG XL The JPEG XL Image Coding System is a royalty-free open standard for a image compression, compressed Raster graphics, raster image format. It defines a graphics file format and the abstract device for coding JPEG XL bitstreams. It is developed by t ...

* JPEG XR *

, image format based on

VP8 VP8 is an open format, open and royalty-free Video coding format, video compression format released by On2 Technologies in 2008. Initially released as a Proprietary software, proprietary successor to On2's previous VP7 format, VP8 was released a ...

References

External links

*
BPG
– image comparison {{Compression formats Animated graphics file formats Graphics file formats Image compression Open formats Computer-related introductions in 2014