DICOM PS3.5 2019b - Data Structures and Encoding

G.2 Byte Segments

A Byte Segment is a series of bytes generated by decomposing the Composite Pixel Code (see PS3.3).

If the Composite Pixel Code is not an integral number of bytes in size, sufficient Most Significant zero bits are added to make it an integral byte size. This is known as the Padded Composite Pixel Code.

The first Segment is generated by stripping off the most significant byte of each Padded Composite Pixel Code and ordering these bytes sequentially. The second Segment is generated by repeating this process on the stripped Padded Composite Pixel Code continuing until the last Pixel Segment is generated by ordering the least significant byte of each Padded Component Pixel Code sequentially.

Note

  1. If Photometric Interpretation (0028, 0004) equals RGB and Bits Allocated equals 8, then three Segments are generated. The first one holds all the Red values, the second all the Green values, and the third all the Blue values.

  2. The use of separate segments implies that the Planar Configuration (0028,0006) could theoretically be 1 for RLE compressed images, but for consistency with other Encapsulated (compressed) Transfer Syntaxes and restrictions on Planar Configuration in many IODs, it may be 0 unless constrained by the IOD.

DICOM PS3.5 2019b - Data Structures and Encoding