Calibration method for telecentric imaging 3D shape measurement system
US10110879B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 2016 |
| Grant date | Oct 23, 2018 |
| Priority date | — |
| Expiry date | Dec 17, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N13/296
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A calibration method is described for a telecentric imaging 3D shape measurement system, including step S1: establishing a telecentric 3D shape measurement system; S2: controlling a telecentric projection equipment to project a sinusoidal fringe pattern to a translation stage, and collecting the sinusoidal fringe pattern by a telecentric camera equipment; moving the translation stage to different depth, then obtaining absolute phase values of a pixel for calibration by a phase-shifting method; and conducting linear fitting on the series of absolute phase values of the pixel and the corresponding depths to obtain a phase-depth conversion of the measurement system; and S3: transforming pixel coordinates on the image plane of the telecentric camera equipment into world coordinates through calibrating parameters of the telecentric camera equipment. A relationship between phase and depth herein is linear, and only needs to calibrate the linearity of one pixel. Therefore, the phase-depth calibration is of small complexity, high precision, good operability and strong practical applicability. Moreover, an orthographic transformation model of camera with bilateral telecentric lens is provid…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.