Phase unwrapping algorithm based on a rank information filter.

A robust phase unwrapping algorithm based on a rank information filter is proposed to retrieve the unambiguous unwrapped phase from noisy wrapped phase images. First, a recursive phase unwrapping program, based on a rank information filter, is proposed to transform the problem of phase unwrapping for wrapped phase into the problem of the state estimation for state variables under the framework of a rank information filter, where a local phase gradient estimator based on the amended matrix pencil model (AMPM) is used to obtain phase gradient information required by the recursive phase unwrapping program. Second, an efficient path-following strategy based on heap-sort is used to guide the phase unwrapping path, which ensures that the recursive phase unwrapping program based on a rank information filter unwraps wrapped phase images along the path from high-quality pixels to low-quality pixels. Finally, the results obtained from synthetic data and experimental measured data demonstrate the effectiveness of the proposed method and show this method can obtain robust solutions from noisy wrapped phase images.