Pearl grading method
US10082491B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 14, 2015 |
| Grant date | Sep 25, 2018 |
| Priority date | — |
| Expiry date | Jul 14, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/10028
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pearl grading method includes the following steps: (1) determining the color type of the pearl to be graded; (2) generating a simulated three-dimensional graph of the pearl to be graded; (3) calculating roundness, so as to obtain a roundness grade; (4) calculating the diameter of the simulated three-dimensional graph, so as to obtain a diameter grade; (5) drawing an illumination-wavelength reflection spectrum; (6) changing a detected part, and drawing an illumination-wavelength reflection spectrum again; (7) repeating the step (6) for at least two times; (8) performing weighted average to obtain a correction curve; and (9) comparing the correction curve with each glossiness grade spectrum baseline, so as to determine a glossiness grade according to the spectrum baseline with the highest coincidence degree. The method has the beneficial effects of low cost, high speed, good result consistency and high detection precision.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.