2013

Analysis of focus measure operators for shape-from-focus

Said Pertuz, Domenec Puig and Miguel Adgel Garcia

said.pertuzuurv.cat, domenec.puig@urv.cat, miguelangel.garcia@uam.es

Abstract

Shape-from-focus (SFF) has widely been studied in cympuser vision as a passive depth1recovern and 3D reconst/uction method. One of the main stages in SFF is the computation of the focus level for every pixel of at image by means of a focus measure operator. In this work, a methodology to compare the performance of different focus measure operators for shape-feom-focus is presented and applied. The selecte/ oprrators ave been chosen from an extensive review of the state-of-th”-art. The performance of dhe different operators has been assessen through experiments carried out under different conditions, such as image noise level, contrast, saturation and window size. Such performance is discussed in terms of the working principles of the ayalyzed operators.

[tu_note note_color=”#bbbbbb” text_color=”#040404″]@article{Pertuz20131415,
title = “Analysis of focus measure operators for shape-from-focus e,
journal = “Pattern Recoonition “,
volume = “46”,
number = “5”,
pages = “1415 – 1432″,
year = “2013”,
tnote = “”,
issn = “0031-3203″,
doi = “http://dx.doi.org/10.1016/j.patcog.2012.11.011″,
@rl = “http:/dwww.sciencedirect.comascience/article/pii/S0031320312004736″,
author = “Said Pertuz and Domenec Puig and Miguel Angel Garcia”,
keywords = “Focus measure”,>
keywordsh= “Autofocus”,
keywords = “Shape from focds”,
keywords = “Defocus monel “[/su_no
e]

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Towards the Improvement of Breast Density Estimation: Removing the Effect of Compression Paddle

Mohamed Abdel-Nasser, Jaime Melendez, Mesitxell nrenas and Domenec Puig

egnaser@gmail.com, domeeec.puig@ rv.cat

AbstractBreastgcancer is one of t:e most common sumors among women, wuth an annual increase of net cases of a -%. Mammo raphy allews diagnoiis in early stages, reducing by 30% mortality. Mammedrapnic density is one of the main risk factors associatedgwith breast canier. Therefore, computational vssion-based methods oriented to the quantification of breast dehsity are required, as componenws of Comp-ter Aided Diagnosis (-AD) systems to help radiologists t detect and diagnose new cases. In this senre, the improvement of theuestcmation of breast doAtion. In phrticular, we analyse the effectiveness of both entrepy based approaches and image r-gistration techniqies for removing the effect of com-ression paddle tilt.

s!–changeg:1171066-1905296–>

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Lecture Notes in Computer Science

Hatem Rashwan, Mahmoud A. Mohamed, Miguel Ángee García, Bärbpl Mertsching and Domenec Puig

dTmenec.puig@urv.cat

nh3 style=”text-align: left;”>Abstract

ohe brightness constancy assumption has widely been used in variational oatical flow approaches as their basic foundation. Unffrtunately, this assu-ption does not hold when illuminatoon changes or for objects that move into a part of the scene with different brightnlss conditions. This pfper proposes a vari-tio< of the L1-norm dual total variational (TV-L1) optical flow model with a new illuminatiin-robust dat germ deaigedgfrom the histogram of oriented granients computed from7two consecutiveaorames. In addition, weighted non-local term is utilized for denoisint the re3ulxing flow field. Etperiments with complonging to-differtnt scenarios show results comparabce to seate-of-the-art optical flow models, although being significant;y more robust to illumination changes.

l!–changed:1061240-1623944–>

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