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US 2024/0179336 A1Published application
Streamed progressive decoding of heif images
AssigneeApple Inc.
InventorsLeo BARNES, Alexandros TOURAPIS
Life of this patent
Estimating the term…
Abstract
Improved still image encoding techniques may include generating first items of a log and second items of coded tile-layer image data, where the log enumerates coding quality levels contained in the second items. The second items may include independent-type items, derived-type items of identity variant, and derived-type items with other variant(s). Such encoding techniques may provide for progressive decoding of images, and may provide for spatially variable encoding quality levels.
Claims20
A method of still image encoding, comprising:
- generating a log of coding quality levels applied to the still image, the log including a plurality of first items corresponding to each quality level that contains references to second items corresponding to the respective quality level;
- for each of a plurality of spatial tiles of the still image, generating a second item at each quality level identified in the log, wherein each second item is one of a plurality of item types, including:
- when a second item has an independent type, encoding a tile at the respective quality without reference to others of the generated second items;
- when a second item has a derived type with an increased quality level, encoding a tile with refinement data at the second item's respective quality level at least in part by reference to another of the generated second items corresponding to its respective tile;
- and
- when a second item has the derived type without an increased quality level, encoding a tile, at least in part by reference to another of the generated second items corresponding to the same tile, and without refinement data at a second, lower coding quality level of a reference tile of the second item.
3 more elements
A method of still image decoding, comprising:
- parsing, from an encoded stream, a log of coding quality levels applied to the still image, the log including a plurality of log items corresponding to each quality level that contains references to second items corresponding to the respective quality level;
- for a plurality of spatial tiles of the still image, parsing, from the encoded stream, a second item at each quality level identified in the log, wherein each second item is one of a plurality of item types;
- in response to determining that a parsed second item has an independent type, decoding the parsed second item at the respective quality without reference to others of the parsed second items to produce a reconstrued tile at the respective quality level;
- in response to determining that a second item has a derived type and includes refinement data, decoding the second item at least in part by reference to another of the parsed second items to produce a reconstrued tile at the parsed second item's respective quality level;
- and
- in response to determining that a parsed second item has a derived type and does not include refinement data, decoding the parsed second item at least in part by reference to another of the parsed second items to produce a reconstrued tile at the referenced second item's respective quality level.
3 more elements
A non-transitory computer readable medium storing instructions of still image decoding that, when executed by a processor, cause the processor to:
- parse, from an encoded stream, a log of coding quality levels applied to the still image, the log including a plurality of log items corresponding to each quality level that contains references to second items corresponding to the respective quality level;
- for a plurality of spatial tiles of the still image, parse, from the encoded stream, a second item at each quality level identified in the log, wherein each second item is one of a plurality of item types;
- in response to determining that a parsed second item has an independent type, decode the parsed second item at the respective quality without reference to others of the parsed second items to produce a reconstrued tile at the respective quality level;
- in response to determining that a second item has a derived type and includes refinement data, decode the second item at least in part by reference to another of the parsed second items to produce a reconstrued tile at the parsed second item's respective quality level;
- in response to determining that a parsed second item has a derived type and does not include refinement data, decode the parsed second item at least in part by reference to another of the parsed second items to produce a reconstrued tile at the referenced second item's respective quality level.
2 more elements
Dependencies are inferred from the claim text.