Absolute phase estimation: adaptive local denoising and global unwrapping
Bioucas-Dias, J.
; Katkovnik, V.
; Astola, J.
; Egiazarian, K.
Applied Optics Vol. 47, Nº 29, pp. 5358 - 5369, October, 2008.
ISSN (print): 1559-128X
ISSN (online): 2155-3165
Scimago Journal Ranking: 1,33 (in 2008)
Digital Object Identifier:
Abstract
The paper attacks absolute phase estimation with a two-step
approach: the first step applies an adaptive local denoising
scheme to the modulo-2pi noisy phase; the second step applies a
robust phase unwrapping algorithm to the denoised modulo-pi
phase obtained in the first step. The adaptive local modulo-2pi
phase denoising is a new algorithm based on local polynomial approximations. The zero-order and the first-order approximations
of the phase are calculated in sliding windows of varying size.
The zero-order approximation is used for point-wise adaptive
window size selection, whereas the first-order approximation is
used for filtering the phase in the obtained windows. For phase
unwrapping, we apply the recently introduced robust (in the
sense of discontinuity preserving) PUMA unwrapping algorithm
[J. Bioucas-Dias and G. Valadao, IEEE Trans. Image Proc.,
vol. 16, no. 3, pp. 698-709 (2007)] to the denoised wrapped phase.
Simulations give evidence that the proposed algorithm yields
state-of-the-art performance, enabling strong noise attenuation
while preserving image details.