Person:
Vargas Balbuena, Javier

First Name

Javier

Last Name

Vargas Balbuena

URI

https://hdl.handle.net/20.500.14352/75168

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Físicas

Department

Óptica

Area

Optica

Identifiers

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Now showing 1 - 8 of 8

Two-step interferometry by a regularized optical flow algorithm
(Optics Letters, 2011) Quiroga Mellado, Juan Antonio; Vargas Balbuena, Javier; Sánchez Sorzano, Carlos Óscar; Estrada, Julio César; Carazo García, José María
A two-step phase-shifting method, that can demodulate open-and closed-fringed patterns without local sign ambiguity is presented. The proposed method only requires a constant phase-shift between the two interferograms. This phase-shift does not need to be known and can take any value inside the range (0, 2 π), excluding the singular case where it corresponds to π. The proposed method is based on determining first the fringe direction map by a regularized optical flow algorithm. After that, we apply the spiral phase transform (SPT) to one of the fringe patterns and we determine its quadrature signal using the previously determined direction. The proposed technique has been applied to simulated and experimental interferograms obtaining satisfactory results. A complete MATLAB software package is provided in [http://goo.gl/Snnz7].
Incremental PCA algorithm for fringe pattern demodulation
(Optics express, 2022) Gómez Pedrero, José Antonio; Estrada, Julio César; Alonso Fernández, José; Quiroga Mellado, Juan Antonio; Vargas Balbuena, Javier
This work proposes a new algorithm for demodulating fringe patterns using principal component analysis (PCA). The algorithm is based on the incremental implantation of the singular value decomposition (SVD) technique for computing the principal values associated with a set of fringe patterns. Instead of processing an entire set of interferograms, the proposed algorithm proceeds in an incremental way, processing sequentially one (as minimum) interferogram at a given time. The advantages of this procedure are twofold. Firstly, it is not necessary to store the whole set of images in memory, and, secondly, by computing a phase quality parameter, it is possible to determine the minimum number of images necessary to accurately demodulate a given set of interferograms. The proposed algorithm has been tested for synthetic and experimental in ter ferograms showing a good performance. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement
Fringe pattern denoising by image dimensionality reduction
(Optics and Lassers in Engineering, 2013) Quiroga Mellado, Juan Antonio; Vargas Balbuena, Javier; Estrada, Julio César; Carazo García, José María; Sánchez Sorzano, Carlos Óscar
Noise is a key problem in fringe pattern processing, especially in single frame demodulation of interferograms. In this work, we propose to filter the pattern noise using a straightforward, fast and easy to implement denoising method, which is based on a dimensionality reduction approach, in the sense of image rank reduction. The proposed technique has been applied to simulated and experimental ESPI interferograms obtaining satisfactory results.
A two steps phase-shifting demodulation method using the VU factorization
(Optics and lassers in engineering, 2021) Estrada, Julio César; Flores, Victor H.; Vargas Balbuena, Javier
In this paper, we present a two steps phase-shifting fringe pattern demodulation method using the VU factorization. Compared with other methods, our proposal is robust to non-constant background illuminations and modulating terms (non-normalized fringes). We use the two given fringe patterns, and from these, we synthetically generate another two images that approach the background illumination in order to obtain a total set of four images. Such set is used in a matrix model that can be factorized using the VU factorization method to determine the modulating phase. Our proposal is able to recover the phase without 1) known phase shift, 2) normalized fringe patterns, and 3) any special non-linear pre-processing. Tests and results with an important representative diversity of interferograms, taken from different experiments, are shown to demonstrate the feasibility of this method.
Robust weighted principal components analysis demodulation algorithm for phase-shifting interferometry
(Optics express, 2021) Vargas Balbuena, Javier; Wang, Shuoyu; Gómez Pedrero, José Antonio; Estrada, Julio César
We present an asynchronous phase-shifting demodulation approach based on the principal component analysis demodulation method that is robust to typical problems as turbulence, vibrations, and temporal instabilities of the optical setup. The method brings together a two-step and a phase-shifting asynchronous demodulation method to share their benefits while reducing their intrinsic limitations. Thus, the proposed approach is based on a two-fold process. First, the modulating phase is estimated from a two-step demodulation approach. Second, this information is used to compute weights to each phase-shifted pattern of the interferogram sequence, which are used in a novel weighted principal component demodulation approach. The proposed technique has been tested with simulated and real interferograms affected by turbulence and vibrations providing very satisfactory results in challenging cases.
Role of the filter phase in phase sampling interferometry
(Optics Express, 2011) Quiroga Mellado, Juan Antonio; Servín Guirado, Manuel; Estrada, Julio César; Vargas Balbuena, Javier; Torre Belizón, Francisco Javier de la
Any linear phase sampling algorithm can be described as a linear filter characterized by its frequency response. In traditional phase sampling interferometry the phase of the frequency response has been ignored because the impulse responses can be made real selecting the correct sample offset. However least squares methods and recursive filters can have a complex frequency response. In this paper, we derive the quadrature equations for a general phase sampling algorithm and describe the role of the filter phase.
Two-step self-tuning phase-shifting interferometry
(Optics Express, 2011) Quiroga Mellado, Juan Antonio; Vargas Balbuena, Javier; Belenguer Dávila, Tomás; Servín Guirado, Manuel; Estrada, Julio César
A two-step self-tuning phase-shifting method is presented. The phase-step between the two interferograms is not known when the experiment is performed. Our demodulating method finds, in a robust way, this unknown phase-step. Once the phase-step is estimated we proceed to phase demodulate the interferograms. Moreover our method only requires the fringe patterns to have a constant unknown phase-shift between them. As a consequence, this technique can be used to demodulate open and closed-fringed patterns without phase-sign ambiguity. The method may be regarded as a self-tuning quadrature filter, which determines the phase-shift between the two fringe patterns and finally estimates the demodulated phase map. The proposed technique has been tested with simulated and real interferograms obtaining satisfactory results.
Regularized least squares phase sampling interferometry
(Optics Express, 2011) Quiroga Mellado, Juan Antonio; Servín Guirado, Manuel; Estrada, Julio César; Vargas Balbuena, Javier
In phase sampling interferometry, existing temporal analysis methods are sensitive to border effects and cannot deal with missing data. In this work we propose a quadrature filter that allows a reliable dynamic phase measurement for every sample, even in the cases involving few samples or missing data. The method is based on the use of a regularized least squares cost function that enforces the quadrature character of the filter. A comparison with existing techniques shows the effectiveness of the proposed method.