Image Pixel
(0028,0103)
Pixel Representation
Keyword: PixelRepresentation
Data representation of pixel samples. 0x0000 = unsigned integer, 0x0001 = 2's complement (signed).
Tag Attributes
- Tag ID
- (0028,0103)
- Compact
- 00280103
- Keyword
- PixelRepresentation
- VR
- US — Unsigned Short
- VM
- 1
- Retired
- No
Module(s)
Image Pixel Module
Engineering Notes
CT images use signed representation (0x0001) because Hounsfield Units include negative values (air = -1000 HU). Using unsigned for CT causes all negative HU values to wrap to large positive numbers.
Troubleshooting
CT images displaying with air as bright white (instead of black) is the classic symptom of wrong Pixel Representation (unsigned when signed is needed).
Common Values
| Value | Meaning |
|---|---|
| 0 | Unsigned integer |
| 1 | Two's complement (signed) — CT, some MR |