A multigrid approach to two-dimensional phase unwrapping
نویسندگان
چکیده
منابع مشابه
A multigrid approach to two-dimensional phase unwrapping
The two-dimensional phase unwrapping problem is studied. Using the minimum Lp-norm approach, we apply three different nonlinear multigrid algorithms for reconstructing surfaces from their “wrapped” values—two classical approaches and a novel Multilevel Nonlinear Method (MNM). The methods prove to be efficient even for difficult problems with noisy and discontinuous original images. The new meth...
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We propose a new technique for two-dimensional phase unwrapping. The unwrapped phase is found as the solution of an inverse problem that consists in the minimization of an energy functional. The latter includes a weighted data fidelity term that favors sparsity in the error between the true and wrapped phase differences, as well as a regularizer based on higher-order total variation. One desira...
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Over the past ten years, many phase unwrapping algorithms have been developed and formulated in a discrete setting. Here we propose a variational formulation to solve the problem. This continuous framework will allow us to impose some constraints on the smoothness of the solution and to implement them efficiently. This method is presented in the one dimensional case, and will serve as a basis f...
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Imaging systems that construct an image from phase information in received signals include synthetic aperture radar (SAR) and optical Doppler tomography (ODT) systems. A fundamental problem in the image formation is phase ambiguity; i.e. it is impossible to distinguish between phases that differ by 2π. Phase unwrapping in two dimensions essentially consists of detecting the pixel locations of t...
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Two-dimensional phase unwrapping is the problem of deducing unambiguous “phase” from values known only modulo 2π. Many authors agree that the objective of phase unwrapping should be to find a (weighted) minimum of the number of places where adjacent discretized phase values differ by more than π. This problem, which is known to be NP-hard, is of considerable practical interest, largely due to i...
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ژورنال
عنوان ژورنال: Numerical Linear Algebra with Applications
سال: 2004
ISSN: 1070-5325
DOI: 10.1002/nla.380