A direct conversion receiver employing a frequency multiplied digital phase-shifting demodulator

1994 ◽  
Vol 77 (4) ◽  
pp. 29-37
Author(s):  
Makoto Hasegawa ◽  
Masahiro Mimura ◽  
Kazuaki Takahashi ◽  
Mitsuo Makimoto
Keyword(s):  
Direct Conversion ◽  
Phase Shifting ◽  
Digital Phase

Single-shot digital phase-shifting Moiré patterns for 3D topography

2020 ◽  
Vol 60 (4) ◽  
pp. A84
Author(s):  
Haiyun Guo ◽  
Haowen Zhou ◽  
Partha P. Banerjee
Keyword(s):  
Phase Shifting ◽  
Single Shot ◽  
Digital Phase ◽  
3D Topography ◽  
Moire Patterns ◽  
Moiré Patterns

Complex Freeform Surface Measurement Based on Stereo Vision and Digital Phase-Shifting Techniques

2013 ◽  
Vol 284-287 ◽  
pp. 623-628
Author(s):  
Jun Yi Lin ◽  
Kai Yong Jiang ◽  
Ming Chang ◽  
Yen Yu Wang
Keyword(s):  
Stereo Vision ◽  
Stereo Matching ◽  
Interpolation Method ◽  
Gray Code ◽  
Phase Shifting ◽  
Surface Measurement ◽  
Probability Method ◽  
Maximum Probability ◽  
Digital Phase ◽  
Shoe Last

In this paper, a method combining stereo vision and digital phase-shifting techniques is presented, which can measure the profile of complex freeform surfaces expeditiously and accurately. A chessboard is used to determine the camera parameters for the camera calibration of the system and the epipolar line rectification is executed based on the stereo calibration result. The stereo matching is processed with the combination of four-step phase-shifting and Gray code techniques, and the maximum probability method is proposed to remove the fringe order confusion problem between Gray code and phase shifting measurement. Bilinear interpolation method is also adopted to improve the speed and accuracy of stereo matching. Experiments were carried out with measuring a step gauge block and a shoe last model. Experimental results show that the measurement can be completed within 3 s for a measuring region of 640 mm × 480 mm, and the average measurement error is less than 0.054 mm.

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