Stereo Pairs Present Attribute
| Tag | (0022,0028) |
|---|---|
| Type | Optional (3) |
| Keyword | StereoPairsPresent |
| Value Multiplicity | 1 |
| Value Representation | Code String (CS) |
The multi-frame pixel data consists of left and right stereoscopic pairs. See Section C.7.6.6.1.3 for further explanation.
Enumerated Values:
- YES
-
- NO
-
Section C.7.6.6.1.3
C.7.6.6.1.3 Stereoscopic Pairs Present
Stereo Pairs Present (0022,0028) shall have the value of YES when frames within a Multi-frame Image are encoded as left and right stereoscopic pairs.
When Stereoscopic Pairs are present, and the pixel data is uncompressed, or compressed with a Transfer Syntax that does not explicitly convey the semantics of stereo pairs, the first and subsequent odd frames (frames numbered from 1) are the left frame of each pair, and the second and subsequent even frames are the right frame of each pair.
If the pixel data is compressed with a Transfer Syntax that does explicitly convey the semantics of stereo pairs, then the identification of the left and right frames in the compressed pixel data will be as defined in the compressed bit stream.
Note
-
For example, the MPEG-4 AVC/H.264 Supplemental Enhancement Information (SEI) frame packing arrangement (FPA) field defines various methods of encoding stereo pairs. See PS3.5 Section 8.2.8 “MPEG-4 AVC/H.264 High Profile / Level 4.2 Video Compression”. Videos encoded with this Transfer Syntax are used for what is colloquially referred to as "3D Television" applications. PS3.5 Section 8.2.9 “MPEG-4 AVC/H.264 Stereo High Profile / Level 4.2 Video Compression” defines a method of encoding stereo pairs without frame packing and with 2D backwards compatibility.
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The presence of Stereo Pairs Present (0022,0028) is independent of the use of Instances of the Stereometric Relationship IOD. In particular, no further description of the method of acquisition of the stereoscopic pairs is required, such as might be present in Attributes of the Stereo Pairs Sequence (0022,0020) of the Stereometric Relationship IOD. The definition of the references to left and right pairs in that IOD prohibit the encoding of the left and right pairs in the same Instance, as distinct for the usage here.
-
Not all multi-frame IODs are sufficiently generic in their description to permit the presence of stereoscopic pairs. E.g., the Video Endoscopic Image IOD, Video Microscopic IOD and Video Photographic IODs are, since they do not specify any conflicting constraints on the meaning of the frames.