Description
DICOM Pixel Spacing order is row then column, in millimeters; distances are in the image plane, not patient-coordinate reconstruction.
An image grid has array indices as well as physical spacing, timing, and signal conventions. A calculation on supplied metadata describes one part of that grid or signal; it does not inspect an image, validate a complete file, or interpret anatomy.
DICOM Pixel Spacing order is row then column, in millimeters; distances are in the image plane, not patient-coordinate reconstruction.
When to use this tool
Use it for dicom pixel spacing row column crosswalk when the required inputs and conventions are already available.
How to use the tool and how it works
- Enter rowOffset, columnOffset, pixelSpacing. Keep parallel arrays aligned and use the stated units and conventions.
- Run the calculation. Correct any input error before interpreting a result.
- Read rowDistanceMm, columnDistanceMm, planarDistanceMm. Inspect any known, defined, inclusion, or boundary flags before interpreting numeric values.
Require exactly two positive pixelSpacing values in row-then-column order. Multiply rowOffset by the first spacing and columnOffset by the second, then return their Euclidean planar distance.1
DICOM Pixel Spacing gives adjacent row spacing followed by adjacent column spacing, in millimeters.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| rowOffset | Signed row displacement in pixel intervals. | Required. Finite number. |
| columnOffset | Signed column displacement in pixel intervals. | Required. Finite number. |
| pixelSpacing | Exactly two positive spacings: adjacent row spacing then adjacent column spacing, in millimeters. | Required. Array of Finite number.; maximum items 256. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| rowDistanceMm | Signed row component in millimeters. | Required. Finite number. |
| columnDistanceMm | Signed column component in millimeters. | Required. Finite number. |
| planarDistanceMm | Nonnegative planar Euclidean distance in millimeters. | Required. Finite number. |
{
"input": {
"rowOffset": 3,
"columnOffset": 4,
"pixelSpacing": [
2,
1
]
},
"output": {
"rowDistanceMm": 6,
"columnDistanceMm": 4,
"planarDistanceMm": 7.211102550927979
}
}Limitations and assumptions
- DICOM Pixel Spacing uses millimeters, so signed component distances and the nonnegative planar distance are in millimeters. Orientation and image position are still needed for patient-coordinate reconstruction.
- The field tables describe structural bounds; the mechanics also state cross-field requirements. Malformed input shapes, disallowed keys, and invalid domains cause input errors. Results must remain finite and within the declared output contract. A successful false flag or zero placeholder is distinct from an error.
- Numeric arithmetic uses binary floating point. Exact comparisons have no hidden tolerance or decimal rounding; negative zero is exported as zero. Decimal-text integer operations retain the exactness specifically stated above.
Alternative or Complementary methods
For dicom pixel spacing row column crosswalk, check the source records and the supplied rule before comparing the result with another method. Use a full image reader and geometry or signal analysis when the task requires interpreting image data.
References
Similar or alternative tools
- DICOM Pixel Representation Signextension Mask
Unsigned-word masking and two-complement interpretation/sign extension for at most 32 stored bits; no endian or transfer-syntax decoding.
- DICOM Planar Configuration Pixel Offset
Uncompressed zero-based sample-element offset for DICOM planar versus interleaved storage, excluding bit packing and frame byte offsets.