TILECOMP

TILECOMP: OP_J2KE, OP_J2KE3D, OP_J2KERGB, OP_J2KP, OP_J2KP3D, OP_J2KPRGB

The TILECOMP structure contains information about the tile component. Tile components are order-sensitive based on the partition ordering.

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typedef struct { DWORD ComponentNumber; DWORD WaveletTransform; DWORD CompressionProfile; DWORD DecompositionLevels; DWORD SkippedLevels; WORD PrecinctWidth; WORD PrecinctHeight; DWORD Flags; DWORD Reserved[6]; } TILECOMP;

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typedef struct {
   DWORD       ComponentNumber;
   DWORD       WaveletTransform;
   DWORD       CompressionProfile;
   DWORD       DecompositionLevels;
   DWORD       SkippedLevels;
   WORD        PrecinctWidth;
   WORD        PrecinctHeight;
   DWORD       Flags;
   DWORD       Reserved[6];
} TILECOMP;

Fields:

Name

Description

ComponentNumber

The index of the component to which this set of compression parameters pertains. Components are numbered from 0 to N-1 as implied by partition ordering, where N is the total number of components. Typically N=1 if the image is gray or N=3 if the image is RGB. This field is ignored for the DftTileComp element of TILE.

WaveletTransform

The Wavelet Transform to use to compress this component

Irreversible or lossy	WT_9_7 (Default)
Reversible or lossless	WT_5_3

CompressionProfile

Reserved for future use.

DecompositionLevels

From 0 to 65535. The actual wavelet decomposition levels to use. 0 is the default (5 levels).

SkippedLevels

Reserved for future use.

PrecinctWidth

PrecinctHeight

Precinct width and height are a power of 2 from 2 to 32768 or 0 for the default size 32768. Ordinarily, the default is best, but for some applications other sizes will have advantages. 128 is best for images provided to OP_JPIPSERVER or OP_TIDP2.

Flags

(Win32/x64 only) Set TCF_Bypass to use the EBCOT encoder selective coding bypass mode. This makes encoding and decoding faster, but at the cost of a few percent larger compressed image.