JPEGksi

JPEGksi is a proposed image compression format in the JPEG family, introduced in informal drafts by a working group associated with the Joint Photographic Experts Group. The intent is to provide improved compression efficiency, richer feature support, and better scalability for contemporary digital imagery while maintaining compatibility with existing JPEG workflows where possible.

Technical characteristics described for JPEGksi include a multiresolution transform, context-adaptive entropy coding, and both lossy and lossless operation. It is imagined to support 8- to 32-bit per channel color, HDR color spaces such as Rec. 2020, and an alpha channel for transparency. The format is proposed to offer progressive decoding, multiple resolution layers, and robust metadata containers for EXIF, XMP, and color management information.

In terms of compatibility and adoption, JPEGksi defines optional backward-compatible profiles intended to allow decoders that only implement baseline JPEG to render a reduced image, while full decoding requires a JPEGksi-capable decoder. This approach aims to ease transitional use without mandating a complete replacement of existing tools.

History and status: the concept circulated in discussions from the 2010s onward; as of 2025, no formal standard has been published by ISO/IEC JPEG or other recognized bodies, and JPEGksi has not achieved widespread adoption. The field currently centers on formats such as JPEG XL and AVIF, which address similar goals.

See also: JPEG, JPEG XL, AVIF, HEIF, JPEG 2000.