JPEG XT is similar in concept to JPEG-HDR. Its precise relationship to JPEG-HDR is not clear; the formats do not appear to be compatible.
All the critical parts of the standard were published as of 2016-10-15. The final part of the original standard was published in 2018-03.
A JPEG XT file contains one or more APP11 segments (see JPEG#Application segments) whose data begins with ASCII "
JP". Note that the signature is just these two bytes, and has no NUL terminator.
Most of these documents are not free to download.
- ISO/IEC 18477-1:2015 - Part 1: Scalable compression and coding of continuous-tone still images
- ISO/IEC 18477-2:2016 - Part 2: Extensions for high dynamic range images
- ISO/IEC 18477-3:2015 - Part 3: Box file format
- ISO/IEC 18477-4:2017 - Part 4: Conformance testing
- ISO/IEC 18477-5:2018 - Part 5: Reference software
- ISO/IEC 18477-6:2016 - Part 6: IDR Integer Coding
- ISO/IEC 18477-7:2016 - Part 7: HDR Floating-Point Coding
- ISO/IEC 18477-8:2016 - Part 8: Lossless and Near-lossless Coding
- ISO/IEC 18477-9:2016 - Part 9: Alpha Channel Coding