DICOM PS3.5 2019a - Data Structures and Encoding

G.5 RLE Header Format

The RLE Header contains the number of RLE Segments for the image, and the starting offset of each of the RLE Segments. Each of these numbers is represented by a UL (unsigned long) value stored in little-endian format. The RLE Header is 16 long words in length. This allows it to describe a compressed image with up to 15 RLE Segments. All unused segments offsets shall be set to zero.

Each of the starting locations for the RLE Segments are byte offsets relative to the beginning of the RLE Header. Since the RLE Header is 16 unsigned longs or 64 bytes, the offset of RLE Segment One is 64.

The following diagram illustrates the ordering of the offsets within the RLE Header.

Table G.5-1. Ordering of the Offsets Within the RLE Header

number of RLE Segments

offset of RLE Segment 1 = 64

offset of RLE Segment 2

. . .

. . .

offset of RLE Segment n

0

0

0


DICOM PS3.5 2019a - Data Structures and Encoding