Outline Deviation Symmetry Check

Audit corresponding measured outline points about caller already-aligned mirror axis, preserving pair deviations; no automatic alignment, mineral shape ideal or inferred optical symmetry.

Description

Mirror-outline comparison requires already aligned corresponding points.

Mirror-outline comparison requires already aligned corresponding points. For a declared y-axis mirror, x coordinates reverse sign while y coordinates agree.^[1]

Audit corresponding measured outline points about caller already-aligned mirror axis, preserving pair deviations; no automatic alignment, mineral shape ideal or inferred optical symmetry.

When to use Outline Deviation Symmetry Check

Use this tool to audit corresponding measured outline points about caller already-aligned mirror axis, preserving pair deviations; no automatic alignment, mineral shape ideal or inferred optical symmetry.

Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.

How to use Outline Deviation Symmetry Check 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 pairedOutlinePointsMm, callerMirrorDeviationToleranceMm using the field table and calculation rules, then run the tool.
Read pairMirrorDeviationDistancesMm, maximumMeasuredMirrorDeviationMm, aboveCallerOutlineTolerance. 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
pairedOutlinePointsMm	Paired outline points mm	list of list of number	Required
callerMirrorDeviationToleranceMm	Caller mirror deviation tolerance mm	number	Required

Enter a nonempty even number of consecutive 2D point pairs in mm and nonnegative tolerance. Compare each pair under y-axis reflection and return all deviations, their maximum and a strict above-tolerance flag.

pair error=hypot(x1+x2,y1−y2)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
pairMirrorDeviationDistancesMm	Pair mirror deviation distances mm	list of number
maximumMeasuredMirrorDeviationMm	Maximum measured mirror deviation mm	number
aboveCallerOutlineTolerance	Above caller outline tolerance	boolean

json

{
  "input": {
    "pairedOutlinePointsMm": [
      [
        1,
        2
      ],
      [
        -1,
        2
      ],
      [
        2,
        3
      ],
      [
        -2.1,
        3
      ]
    ],
    "callerMirrorDeviationToleranceMm": 0.05
  },
  "output": {
    "pairMirrorDeviationDistancesMm": [
      0,
      0.10000000000000009
    ],
    "maximumMeasuredMirrorDeviationMm": 0.10000000000000009,
    "aboveCallerOutlineTolerance": true
  }
}

Limitations and assumptions

No automatic registration or ideal mineral shape is inferred. Optical symmetry is a separate measurement.

Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Matrices are limited to 128 rows and 128 entries per row; other numeric lists are limited to 100,000 entries. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Pearl Shape Symmetry Rater: Audit centered pearl outline through principal second-moment axes and radial RMS residual, distinct from paired mirror errors; sampling must be comparable, not a pearl shape/market grade or 3D reconstruction. For a complementary task, use Optical Symmetry Score: Audit aligned image brightness asymmetry about declared horizontal/vertical mirror axes, normalized to total flux; unlike paired physical outline error, illumination/registration remain confounders and no automatic alignment.

References

Outline Deviation Symmetry Check — tool.io

Similar or alternative tools

Pearl Shape Symmetry Rater
Audit centered pearl outline through principal second-moment axes and radial RMS residual, distinct from paired mirror errors; sampling must be comparable, not a pearl shape/market grade or 3D reconstruction.
Optical Symmetry Score
Audit aligned image brightness asymmetry about declared horizontal/vertical mirror axes, normalized to total flux; unlike paired physical outline error, illumination/registration remain confounders and no automatic alignment.