Quiroga Mellado, Juan Antonio

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First Name
Juan Antonio
Last Name
Quiroga Mellado
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Físicas
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Now showing 1 - 8 of 8
  • Publication
    Fourier transform method for automatic processing of moiré deflectograms
    (Spie-Soc Photo-Optical Instrumentation Engineers, 1999-06) Quiroga Mellado, Juan Antonio; Crespo Vázquez, Daniel; Bernabeu Martínez, Eusebio
    In this work, a Fourier transform technique for automatic analysis of moire deflectograms is presented. A squared grating is used to multiplex the information of the deflection in two orthogonal directions in one image. This procedure avoids the necessity of rotating the gratings to obtain the complete deflection information. With this method only two fringe patterns. reference and distorted, are needed to determine the complete deflection information. To deal with irregularly shaped processing areas, a Gerchberg extrapolation method is used. The automatic determination of the carrier as well as the size and position of the reconstruction windows permit the complete and automatic measurement of the deflection produced by an ophthalmic lens in two orthogonal directions. Afterwards, the refractive power maps can be obtained, Experimental results obtained with a progressive addition lens are presented and comparison with measurements obtained with a commercial focimeter are shown showing a good agreement.
  • Publication
    Recent advances in automatic demodulation of single fringe patterns
    (Springer Verlag Berlin, 2006) Quiroga Mellado, Juan Antonio; Crespo Vázquez, Daniel; Gómez Pedrero, José Antonio; Martínez Antón, Juan Carlos
  • Publication
    Automatic demodulation of single-image fringe patterns with application in the evaluation of external defects in aeronautical surfaces by shadow-moire
    (VDI-VDE - Verlag GMBH, 2004) Quiroga Mellado, Juan Antonio; Crespo Vázquez, Daniel; Fournier, N.; Martínez Antón, Juan Carlos
    Automatic demodulation of single-image fringe patterns is of great importance in research areas were it is difficult to apply standard phase evaluation techniques such as phase sampling or Fourier transform methods. In this work we will present recent advances in the automatic demodulation of single-image fringe patterns. In particular we have used two methods for the demodulation process: the regularized phase tracker (RPT) and the isotropic quadrature transform (IQT). For a reliable and automatic demodulation of real fringe patterns by means of the RPT and the IQT techniques we have developed strategies for fringe pattern normalization, modulo 2π fringe orientation computation and adaptive processing, which all together configure a reliable and fast demodulation scheme. We have applied these techniques in the evaluation of external defects in aeronautical surfaces by the shadow moire technique and for this purpose a software package has been developed that works together with an in-line inspection system for indentation assessment designed by the company NDT-Expert. Experimental results of the system will be shown and performance will be discussed.
  • Publication
    Adaptive spatiotemporal structured light method for fast three-dimensional measurement
    (Spie-Soc Photo-Optical Instrumentation Engineers, 2006-10) Quiroga Mellado, Juan Antonio; Crespo Vázquez, Daniel; Vargas Balbuena, Javier; Gómez Pedrero, José Antonio
    We present a high-speed 3-D spatiotemporal shape measurement technique by means of structured light. Current methods use a constant number of images that do not take into account the available temporal continuity of the measured object. That is, they focus on acquiring and processing as quickly as possible a fixed number of images to solve for the correspondence problem and later obtain the 3-D shape by triangulation. The number of images used imposes the use of some spatial support. The major contribution of our research is a new spatiotemporal scheme that, depending on the object's movement, adaptively uses the maximum number of projected images consistent with the local temporal continuity, therefore solving the correspondence problem with the minimum possible spatial support for each position. This is achieved by the use of a hybrid color pattern composed of an analog sinusoidal periodic code in the red channel and a digital binary spatial code in the blue channel that is cyclically displaced. No subpixel calculation is used and it is possible to implement error correction strategies that make the method fast and reliable, enabling dynamic online 3-D measurement of objects in movement.
  • Publication
    XtremeFringe: state-of-the-art software for automatic processing of fringe patterns
    (SPIE--The International Society for Optical Engineering, 2007) Quiroga Mellado, Juan Antonio; Crespo Vázquez, Daniel; Gómez Pedrero, José Antonio
    XtremeFringe is a new library for fringe pattern processing which incorporates modem methods for automatic analysis including fringe pattern demodulation, fringe pattern filtering and phase unwrapping methods. XtremeFringe (R) is written in C# and is usable as an assembly from any NET language (C#, C++, .NET, J#) and additionally as a Matlab toolbox, which ensures an easy adaptation in custom applications, providing the user with a versatile and powerful tool for fringe pattern analysis in a flexible way. The functions of XtremeFringe are suitable to be employed in metrological applications such interferometry, photoelasticity, Moire techniques, holography, etc. supplying the user with up-to-date fringe analysis tools. In this work, we demonstrate the capabilities of the XtremeFringe library, processing different examples showing the ability of the library to analyze complex fringe patterns in a fast, reliable and automatic way.
  • Publication
    Fourier based design of asynchronous phase detection algorithms
    (SPIE--The International Society for Optical Engineering, 2007) Quiroga Mellado, Juan Antonio; Gómez Pedrero, José Antonio; Crespo Vázquez, Daniel
    Phase detection is an important issue when dealing with optical metrology techniques for which the magnitude to be measured is encoded through the phase of a given fringe pattern. Asynchronous phase detection techniques are employed when the rate of phase change (frequency) it is not known. These techniques always present a variable frequency response, in other words, their ability to recover properly the phase depends strongly on the local frequency. In many experiments, it is possible to have a rough knowledge about the range of frequencies involved. Therefore, it constitutes a great advantage to have a procedure to design an asynchronous demodulation method which is suited to a particular frequency response for a given experiment. In this way, we get a better behaviour against noise which leads to more accurate and reliable phase extraction. In this work we present a technique to design asynchronous demodulation algorithms with a desired frequency response using a Fourier-based technique. The method allows the design of algorithms with a limited algebraic error in the recovered phase which have better properties than standard asynchronous phase detection techniques as it is shown in numeric and real experiments.
  • Publication
    Automatic techniques for evaluation of moire deflectograms
    (SPIE--The International Society for Optical Engineering, 1999) Quiroga Mellado, Juan Antonio; Villa Hernández, José de Jesús; Crespo Vázquez, Daniel
    In this work we present two methods for the analysis of moire deflectograms. The first method is a Fourier-transform technique. The second method uses a regularization based method. Both methods are applied to realistic deflectograms and their performances are discussed.
  • Publication
    New method for three-dimensional shape registration of prismatic objects
    (Spie-Society of Photo-Optical Instrumentation Engineers, 2006-02) Quiroga Mellado, Juan Antonio; Vázquez Moliní, Daniel; Crespo Vázquez, Daniel
    A new method for 3-D shape registration of prismatic objects is presented. The term prismatic object denotes any object with sharp boundaries on its surface. These kinds of objects cannot be correctly registered with typical existing methods, which require smooth overlapping of the whole surface. The method presented here is based on the use of reference marks, placed on a planar glass plate that is attached to the prismatic object. Two 3-D range measurements of the object are then acquired, before and after rotating the object by approximately 180 deg. Using the reference marks on the glass and two different calibrations of the 3-D range scanning system, these two range measurements can be correctly merged to provide a full 3-D range scan of the prismatic object.