Description
Return photographic reference-patch area share and count.
Conservation records distinguish sampled support, retained material, environmental bands and time-dependent model terms. A caller-supplied band or decay constant does not establish an appropriate preservation target. Local bookkeeping and simple exponential response models require separate evidence about the object and its environment.
Return photographic reference-patch area share and count.
When to use this tool
Use Photo Reference Patch Area Share when checking the stated sampling, material balance or environmental-response convention.
How to use the tool and how it works
- Enter patchAreas, referencePatch, imageArea. Follow any array-alignment requirements below. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read referenceArea, share, patchCount. Use the output convention below.
Return photographic reference-patch area share and count. Require aligned arrays, nonnegative patch areas totaling <= imageArea and imageArea > 0; sum flagged patch areas, divide by image area, count true flags.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| patchAreas | Patch Areas | Required. Array of finite number; minimum 0; maximum items 256. |
| referencePatch | Reference Patch | Required. Array of boolean; maximum items 256. |
| imageArea | Image Area | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| referenceArea | Reference Area | Required. Finite number. |
| share | Dimensionless reported share using the selected denominator; not a probability estimate. | Required. Finite number. |
| patchCount | Patch Count | Required. Safe integer. |
{
"input": {
"patchAreas": [
10,
20,
30
],
"referencePatch": [
true,
false,
true
],
"imageArea": 100
},
"output": {
"referenceArea": 40,
"share": 0.4,
"patchCount": 2
}
}Limitations and assumptions
- Zero-area flagged patches still count; no color calibration, patch recognition or actual image quality is verified.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Review verified records and the object-specific preservation assessment with a qualified conservator for actual sampling, display or treatment decisions.
References
Similar or alternative tools
- Object Surface Sampling Fraction
Return object surface sampling fraction.
- Canvas Tension Edge Force Density Tool
Measured edge-force density only; the explicit reference is not a conservation safety threshold.