Results 161 to 170 of about 4,611 (209)

Phase unwrapping by factorization

IEEE Transactions on Acoustics, Speech, and Signal Processing, 1982
An algorithm for the numerical factorization of very high degree but well-conditioned polynomials is developed. This is used to factor the z- transform of finite-length signals, and the zeros are used to calculate the unwrapped phase. The method has been tested on signals up to 512 points in length.
Steiglitz, Kenneth, Dickinson, Bradley
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Phase unwrapping by blocks

Measurement, 1999
Abstract A method of 2-dimensional phase-unwrapping by blocks is presented in this paper. This method combines the advantages of both conventional phase-unwrapping algorithm and cellular-automata unwrapping algorithm. With this concept, a fast, robust and stable phase unwrapping for phase maps of different sizes can be achieved by utilising different
Boxiong Wang, Yuqing Shi, T. Pfeifer, H. Mischo   +3 more
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Noise-immune phase unwrapping algorithm

Applied Optics, 1989
A new phase unwrapping algorithm is proposed which combines noise immunity with computational efficiency. It is based on the requirement that the unwrapped map should be independent of the route by which unwrapping takes place.
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Phase unwrapping by region growing

Applied Optics, 2003
The phase unwrapping problem consists in mingling out an integer field whose values make the original wrapped phase field continuous. Even if in principle the problem is very simple--a direct integration of the wrapped phase field suffices--in the presence of noise and/or undersampling, the solution is no longer unique and the direct integration ...
openaire   +3 more sources

Phase Unwrapping Algorithms: A Comparison

2000
Over the last few years a great deal of work has been done to improve the reliability of phase unwrapping algorithms. Many articles are to be found in the technical literature claiming the robustness and noise immunity of the proposed algorithm.
BALDI, ANTONIO, BERTOLINO, FILIPPO, GINESU, FRANCESCO   +2 more
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Swarm-based algorithm for phase unwrapping

Applied Optics, 2014
A novel algorithm for phase unwrapping based on swarm intelligence is proposed. The algorithm was designed based on three main goals: maximum coverage of reliable information, focused effort for better efficiency, and reliable unwrapping. Experiments were performed, and a new agent was designed to follow a simple set of five rules in order to ...
Lucas, da Silva Maciel, Armando G, Albertazzi   +1 more
openaire   +2 more sources

Singularity-Spreading Phase Unwrapping

IEEE Transactions on Geoscience and Remote Sensing, 2007
How to process phase singular points (SPs), or residues, is a difficult problem in a 2-D phase-unwrapping process to generate digital elevation maps (DEMs). Although the minimum-cost network-flow method is an effective and widely used technique, some problems still remain.
R. Yamaki, A. Hirose
openaire   +1 more source

Phase Unwrapping with Phase-Singularity Spreading

2006 IEEE International Symposium on Geoscience and Remote Sensing, 2006
We propose a novel phase unwrapping method where we spread the singularity in phase map with fractional phase compensators. We find that the obtained digital elevation maps have higher quality than those obtained in conventional network programming method. In addition, the calculation cost is very small.
A. Hirose, R. Yamaki
openaire   +1 more source

Light-field-based absolute phase unwrapping

Optics Letters, 2018
Ambiguity caused by a wrapped phase is an intrinsic problem in fringe projection-based 3D shape measurement. Among traditional methods for avoiding phase ambiguity, spatial phase unwrapping is sensitive to sensor noise and depth discontinuity, and temporal phase unwrapping requires additional encoding information that leads to an increase of image ...
Zewei Cai, Xiaoli Liu, Zhizhen Chen, Qijian Tang, Bruce Z. Gao, Giancarlo Pedrini, Wolfgang Osten, Xiang Peng   +7 more
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Multiresolution phase unwrapping for SAR interferometry

IEEE Transactions on Geoscience and Remote Sensing, 1999
An approach to two-dimensional (2D) phase unwrapping for synthetic aperture radar (SAR) interferometry is presented, based on separate steps of coarse phase and fine phase estimation. A technique called adaptive multiresolution is introduced for local fringe frequency estimation, in which difference frequencies between resolution levels are estimated ...
Davidson, Gordon, Bamler, Richard
openaire   +2 more sources