Description
DICOM default LINEAR VOI boundaries c-0.5 plus/minus (w-1)/2; width one is a threshold and this tool does not implement LINEAR_EXACT or SIGMOID.
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 default LINEAR VOI boundaries c-0.5 plus/minus (w-1)/2; width one is a threshold and this tool does not implement LINEAR_EXACT or SIGMOID.
When to use this tool
Use it for dicom window center width domain bound when the required inputs and conventions are already available.
How to use the tool and how it works
- Enter center, width. Use the stated units and boundary conventions.
- Run the calculation. Correct any input error before interpreting a result.
- Read lowerBoundary, upperBoundary, thresholdOnly. Inspect any known, defined, inclusion, or boundary flags before interpreting numeric values.
Require width at least one and calculate lower=center-0.5-(width-1)/2 and upper=center-0.5+(width-1)/2. Set thresholdOnly exactly when width equals one.1
DICOM default LINEAR windowing requires width at least one; width one is a threshold case.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| center | Center | Required. Finite number. |
| width | Width | Required. Finite number; minimum 1. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| lowerBoundary | Lower Boundary | Required. Finite number. |
| upperBoundary | Upper Boundary | Required. Finite number. |
| thresholdOnly | Threshold Only | Required. Boolean. |
{
"input": {
"center": 40,
"width": 400
},
"output": {
"lowerBoundary": -160,
"upperBoundary": 239,
"thresholdOnly": false
}
}Limitations and assumptions
- This is the default LINEAR convention, not a general window-function evaluator. A true thresholdOnly flag identifies the degenerate endpoint case without producing displayed pixels.
- 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 window center width domain bound, 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 Window Level Endpoint
Compute DICOM default LINEAR window thresholds c−0.5±(w−1)/2; not LINEAR_EXACT or SIGMOID.
- DICOM Frame Increment Time Index Term
Constant Frame Time coordinate for one zero-based frame index; not a variable Frame Time Vector or acquisition datetime parser.