siz_params

Manages the information associated with a JPEG2000 SIZ marker segment. There is only one of these per image — i.e., tile-specific and component-specific forms of this parameter class (cluster type) are both disallowed.

The cluster name is "SIZ", but you are recommended to use the macro SIZ_params, in functions which take a cluster name like kdu_params::access_cluster.

The following attributes are defined. For an explanation of pattern strings, consult the comments appearing with kdu_params::parse_string.

• Macro = Sprofile; Pattern = "I" — Restricted profile to which the code-stream conforms. The value must be an integer in the range 0 to 2, where Profile-0 is the most restrictive and Profile-2 places no restrictions on the code-stream other than those defined in ISO/IEC 15444-1 (JPEG2000, Part 1). If the profile is insufficient, the system will generate a warning at the point where it first encounters an inconsistency; this might not occur until near the end of the processing in certain rare circumstances. Defaults to Profile-2.
• Macro = Ssize; Pattern = "II" — Canvas dimensions: vertical dimension first. For compressors, this will normally be derived from the dimensions of the individual image components. Explicitly supplying the canvas dimensions may desirable if the source image files do not indicate their dimensions, or if custom sub-sampling factors are desired.
• Macro = Sorigin; Pattern = "II" — Image origin on canvas: vertical coordinate first. Defaults to {0,0}, or the tile origin if one is given.
• Macro = Stiles; Pattern = "II" — Tile partition size: vertical dimension first. Defaults to {0,0}.
• Macro = Stile_origin; Pattern = "II" — Tile origin on the canvas: vertical coordinate first. Defaults to {0,0}].
• Macro = Scomponents; Pattern = "I" — Number of image components. For compressors, this will normally be deduced from the number and type of image files supplied to the compressor.
• Macro = Ssigned; Pattern = "B", [MULTI_RECORD, CAN_EXTRAPOLATE] — Indicates whether each image component contains signed or unsigned sample values. For compressors, this will normally be deduced from the image files supplied to the compressor, but may be explicitly set if raw input files are to be used. The last supplied identifier is repeated indefinitely for " all remaining components.
• Macro = Sprecision; Pattern = "I", [MULTI_RECORD, CAN_EXTRAPOLATE] — Indicates the bit-depth of each image component. For compressors, this will normally be deduced from the image files supplied to the compressor, but may be explicitly set if raw input files are to be used. The last supplied value is repeated indefinitely for all remaining components.
• Macro = Ssampling; Pattern = "II", [MULTI_RECORD, CAN_EXTRAPOLATE] — Indicates the sub-sampling factors for each image component. In each record, the vertical factor appears first, followed by the horizontal sub-sampling factor. The last supplied record is repeated indefinitely for all remaining components. For compressors, a suitable set of sub-sampling factors will normally be deduced from the individual image component dimensions.
• Macro = Sdims; Pattern = "II", [MULTI_RECORD, CAN_EXTRAPOLATE] — Indicates the dimensions (vertical, then horizontal) of each individual image component. The last supplied record is repeated indefinitely for all remaining components. For compressors, the image component dimensions will normally be deduced from the image files supplied to the compressor, but may be explicitly set if raw input files are to be used.

Although the JPEG2000 SIZ marker cannot represent negative coordinates, it is particularly convenient to allow this object to store and report negative coordinates. These should not trouble applications which interface with it, since all of the algebraic properties of the coorinate system still hold. Negative coordinates will be converted into appropriate non-negative coordinates only when a valid marker segment must be written out — to do this the write_marker_segment function must examine various cod_params attributes from every tile-component in the image to determine appropriate offsets to the negative coordinates which will not alter the interpretation of the canvas coordinate system.

For the above reason, you should avoid writing a SIZ marker segment (calling kdu_params::generate_marker_segments) until all code-stream parameters have been finalized for all tiles and tile-components.

siz_params {Java: Siz_params}