Scintillation Pattern Index
Integrate measured temporal brightness variation under piecewise-linear frames, retaining actual exposure; scalar scintillation proxy is not complete observer-dependent sparkle or commercial grade.
Description
Temporal scintillation is variation of brightness as viewing conditions change.
Temporal scintillation is variation of brightness as viewing conditions change. A time-weighted scalar proxy depends on the sampled exposures and interpolation model.1
Integrate measured temporal brightness variation under piecewise-linear frames, retaining actual exposure; scalar scintillation proxy is not complete observer-dependent sparkle or commercial grade.
When to use Scintillation Pattern Index
Use this tool to integrate measured temporal brightness variation under piecewise-linear frames, retaining actual exposure; scalar scintillation proxy is not complete observer-dependent sparkle or commercial grade.
Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.
How to use Scintillation Pattern Index and understand its results
- Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.
- Enter frameTimesSeconds, measuredFacetBrightness using the field table and calculation rules, then run the tool.
- Read relativeTemporalScintillationRms, observedBrightnessVariationPerSecond. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| frameTimesSeconds | Frame times seconds | list of number | Required |
| measuredFacetBrightness | Measured facet brightness | list of number | Required |
Use increasing frame seconds and aligned nonnegative brightness with positive time-mean brightness. Integrate linearly interpolated brightness by trapezoids and squared departures exactly per segment; return relative temporal RMS and sum of absolute adjacent brightness changes divided by duration.
Paired lists must be nonempty and have equal lengths. Each sequence checked for increasing order must contain at least two strictly increasing values.
relative RMS=sqrt(time-integrated squared brightness departure/duration)/mean brightness Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| relativeTemporalScintillationRms | Relative temporal scintillation rms | number |
| observedBrightnessVariationPerSecond | Observed brightness variation per second | number |
{
"input": {
"frameTimesSeconds": [
0,
1,
3
],
"measuredFacetBrightness": [
1,
3,
1
]
},
"output": {
"relativeTemporalScintillationRms": 0.28867513459481287,
"observedBrightnessVariationPerSecond": 1.3333333333333333
}
}Limitations and assumptions
The result is not complete observer-dependent sparkle or a commercial grade. Unsampled motion is not reconstructed.
Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Contrast Pattern Grade Estimator: Grade measured spatial RMS luminance contrast under caller independent bands and physical patch areas; differs from temporal scintillation, no laboratory cut grade or perceptual preference is inferred. For a complementary task, use Brilliance Index Approximation: Aggregate independently measured returned/incident optical flux under stated matched angular exposures; no faceted ray-trace, perceptual brilliance grade or radiometric completeness inferred.
References
-
Scintillation Pattern Index — tool.io
Similar or alternative tools
- Contrast Pattern Grade Estimator
Grade measured spatial RMS luminance contrast under caller independent bands and physical patch areas; differs from temporal scintillation, no laboratory cut grade or perceptual preference is inferred.
- Brilliance Index Approximation
Aggregate independently measured returned/incident optical flux under stated matched angular exposures; no faceted ray-trace, perceptual brilliance grade or radiometric completeness inferred.