Results 131 to 140 of about 2,155 (180)
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Phase-Shifting Temporal Phase Unwrapping Algorithm for High-Speed Fringe Projection Profilometry
IEEE Transactions on Instrumentation and Measurement, 2023Haihua An, Yiping Cao, Hongmei Li
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Temporal phase unwrapping of digital hologram sequences
Applied Optics, 2003A method for recording and evaluating digital image-plane holograms is presented. Hundreds of holograms of an object that has been subjected to dynamic deformation (e.g., vibrations) are recorded. The phase of the wave front is calculated from the recorded holograms by use of a two-dimensional digital Fourier-transform method.
Giancarlo, Pedrini +3 more
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Shape measurement by temporal phase unwrapping: comparison of unwrapping algorithms
Measurement Science and Technology, 1997Projected fringes can be used to measure surface profiles unambiguously, even in the presence of surface discontinuities, if the fringe pitch is changed over time. We investigate by numerical, analytical and experimental means the reliability of two recently proposed algorithms for unwrapping the resulting phase histories.
J M Huntley, H O Saldner
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Temporal Phase Unwrapping in Structured Perfilometry
AIP Conference Proceedings, 2008In the perfilometry by means of structured light there are two techniques that are the most used: fringe projection and Moire. The reconstruction of the object surface with inherently discontinuous or prominent slopings, is usually a difficult problem by using standard phase unwrapping technique i.e. the spatial unwrapping.
J. Garzón +5 more
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A generalized temporal phase unwrapping algorithm
SPIE Proceedings, 2007A generalized temporal phase unwrapping (GTPU) algorithm is proposed for absolute phase measurement of object surfaces with complex topography. Comparing with the classical TPU algorithms, GTPU shows more robust and has better noise immunity and less computational complexity.
Jindong Tian, Xiang Peng, Xiaobo Zhao
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Temporal phase-unwrapping algorithm for automated interferogram analysis
Applied Optics, 1993A new algorithm is proposed for unwrapping interferometric phase maps. Existing algorithms search the two-dimensional spatial domain for 2π discontinuities: only one phase map is required, but phase errors can propagate outward from regions of high noise, corrupting the rest of the image.
J M, Huntley, H, Saldner
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Robustness of reduced temporal phase unwrapping in the measurement of shape
Applied Optics, 2001The predictions of success rate and depth uncertainty for the negative exponential sequence used for temporal phase unwrapping of shape data are generalized to include the effect of a reduced sequence and speckle noise in single-channel and multichannel systems, respectively. To cope with the reduction of the sequence, a scaling factor is introduced. A
L, Kinell, M, Sjödahl
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Temporal phase-unwrapping of static surfaces with 2-sensitivity fringe-patterns
Optics Express, 2015 Here we describe a 2-step temporal phase unwrapping formula that uses 2-sensitivity demodulated phases for measuring static surfaces. The first phase demodulation has at most 1-wavelength sensitivity and the second one is G-times (G>>1.0) more sensitive.
Manuel Servin +2 more
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Temporal phase unwrapping applied to wavelength-scanning interferometry
Applied Optics, 2000We demonstrate the use of temporal phase unwrapping in combination with wavelength-scanning interferometry. Two unwrapping strategies are considered: fitting to a reversed exponential sequence and complex Fourier-transform ranging. Measurement of a 10-microm step by use of an external-cavity laser diode is discussed.
L, Paulsson +3 more
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Temporal phase unwrapping with a lightweight deep neural network
Optics Frontier Online 2020: Optics Imaging and Display, 2020Absolute phase unwrapping is important for optical phase-based three-dimensional (3D) measurements of isolated objects or discontinuous surfaces. For fringe projection profilometry, the fringe order of each stripe can be obtained uniquely by temporal phase unwrapping (TPU) that employs at least two different phase maps of the same measured scene.
Kai Liu, Yuzhen Zhang
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