Overview of JPEG XS

The JPEG XS (ISO/IEC 21122) standard specifies a compression technology with an end-to-end latency of a few lines, at a low implementation complexity. For example, this allows hardware implementations that do not require external memory. Its design offers various degrees of parallelism allowing for efficient implementation on various platforms such as FPGAs, ASICs, CPUs and GPUs. In addition, JPEG XS excels with high multi-generation robustness and is particularly optimized for visual lossless compression as defined in ISO/IEC 29170-2 for both natural and synthetic images. Typical compression ratios are up to 10:1 for 4:4:4, 4:2:2, and 4:2:0 images but can also be higher depending on the nature of the image or the requirements of the targeted application. It supports various pixel formats, including raw Bayer, classic RGB and the typical YUV representations, all up to 16 bits per component. Moreover, the codec allows for a very precise bit-rate control to accurately match the available bandwidth, e.g. Gigabit Ethernet, and it offers an end-to-end delay equal to a fraction of a frame. The standard also offers lossless compression of image data with a precision of up to 12-bits per component.

All of these properties allow JPEG XS to be applied in applications which transported uncompressed image data before. This includes, among others, professional video links (3G/6G/12G-SDI), IP transport (SMPTE 2022-5/6 & SMPTE 2110), real-time video storage, memory buffers, omni-directional video capture system, head-mounted displays for Virtual or Augmented Reality and image sensor compression – i.e. for the Automotive Industry and for high-end professional photography. By these means, systems can offer increased resolutions and frame rates while retaining visually lossless quality.

More detailed information is available in the whitepaper on JPEG XS.

JPEG XS is a multi-part specification including the following parts:

Part 1: Core coding system

JPEG XS Part 1 (ISO/IEC 21122-1) 2nd edition normatively defines how a compressed JPEG XS codestream can be transformed into a decoded image in a bit exact manner. Moreover, it informatively explains the key algorithms enabling an encoder to generate a JPEG XS codestream.

Part 2: Profiles and buffer models

JPEG XS Part 2 (ISO/IEC 21122-2) 2nd edition ensures interoperability between different implementations by specifying typical codestream parameterizations and properties. This allows deriving the hardware and software requirements for different purposes such as high compression ratios, low memory or low logic implementations. Moreover, implementation guidelines inform about how to achieve low latency implementations.

Part 3: Transport and container

JPEG XS Part 3 (ISO/IEC 21122-3) 2nd edition defines how to embed a JPEG XS codestream into a more descriptive file format. Moreover, it contains all definitions that are necessary to transport a JPEG XS codestream by means of a transmission channel using existing transmission protocols defined by different standardization bodies.

Part 4, Conformance testing

JPEG XS Part 4 defines conformance testing of JPEG XS. A second edition is currently under development, defining a new relaxed conformance point that allows even faster decoder implementations.

Part 5, Reference software

JPEG XS Part 5 provides the JPEG XS reference software. A second edition is currently under development.