Optical three-dimensional profilometry method based on processing SPECKLE images in partially coherent light, and interferometer implementing such a method
US5870196A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1996 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Oct 16, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/2441
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical three-dimensional profilometry method in which are recorded SPECKLE images formed by the interference, due to different optical paths, of the rays reflected/diffused by a rough object and the rays generated by a beam source. The method presents a number of processing steps including the steps of digitizing a first SPECKLE image, modifying the optical path difference, and digitizing a second SPECKLE image recorded after modifying the optical path difference. The difference in the modulus of the corresponding pixels of the first and second digitized images is determined to generate a difference image which is subsequently analyzed. A first arbitrary value is assigned to all the difference image pixels exceeding a given threshold value, and a second arbitrary value is assigned to all the difference image pixels of a value below the threshold. The binary image so generated is processed to generate an artificial image in which all the binary image pixels equal to the second arbitrary value are assigned a zero value, and all the binary image pixels equal to the first arbitrary value are assigned a current processing step value. The processing steps are repeated cyclically for …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.