ITU-T Recommendations

This Recommendation | International Standard defines a set of lossless (bit-preserving) and lossy compression methods for coding bi-level, continuous-tone grey-scale, palletized colour, or continuous-tone colour digital still images.

This Recommendation | International Standard:

– specifies decoding processes for converting compressed image data to reconstructed image data;

– specifies a codestream syntax containing information for interpreting the compressed image data;

– specifies a file format;

– provides guidance on encoding processes for converting source image data to compressed image data;

– provides guidance on how to implement these processes in practice.

This edition includes the following changes relative to the previous edition:

– addition of Profile marker segment;

– addition of Extended capabilities marker segment;

– addition of Table A.55 to indicate valid Profile number values;

– clarification of Table A.13 and Table A.19, making it explicit that some MSBs are reserved for future use;

– updating of Table A.10 to indicate that the Profile marker segment is used to indicate the Profile to which the codestream conforms.

NOTE – As this specification was first published as common text only after ISO/IEC JTC1 had approved the first edition in 2000, edition numbers in the ITU and ISO/IEC versions are offset by one. This is the third edition of ITU‑T T.800 and the fourth edition of ISO/IEC 15444-1.