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Albert Van Eeckhout

Bio: Albert Van Eeckhout is an academic researcher from Autonomous University of Barcelona. The author has contributed to research in topics: Polarimetry & Mueller calculus. The author has an hindex of 6, co-authored 18 publications receiving 115 citations.

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Journal ArticleDOI
TL;DR: The interest of using the indices of polarimetric purity (IPPs) to the inspection of biological tissues is highlighted and a pseudo-colored encoding of the IPP information that leads to an improved visualization of samples is proposed that opens the possibility of tailored adjustment of tissues contrast by using customized pseudo- colored images.
Abstract: We highlight the interest of using the indices of polarimetric purity (IPPs) to the inspection of biological tissues. The IPPs were recently proposed in the literature and they result in a further synthetization of the depolarizing properties of samples. Compared with standard polarimetric images of biological samples, IPP-based images lead to larger image contrast of some biological structures and to a further physical interpretation of the depolarizing mechanisms inherent to the samples. In addition, unlike other methods, their calculation do not require advanced algebraic operations (as is the case of polar decompositions), and they result in 3 indicators of easy implementation. We also propose a pseudo-colored encoding of the IPP information that leads to an improved visualization of samples. This last technique opens the possibility of tailored adjustment of tissues contrast by using customized pseudo-colored images. The potential of the IPP approach is experimentally highlighted along the manuscript by studying 3 different ex-vivo samples. A significant image contrast enhancement is obtained by using the IPP-based methods, compared to standard polarimetric images.

36 citations

Journal ArticleDOI
TL;DR: It is proved how differences in the depolarizing capability of samples, not seen by the commonly used depolarization index PΔ, are identified by the IPPs.
Abstract: In this work, we discuss the interest of using the indices of polarimetric purity (IPPs) as a criterion for the characterization and classification of depolarizing samples. We prove how differences in the depolarizing capability of samples, not seen by the commonly used depolarization index PΔ, are identified by the IPPs. The above-stated result is analyzed from a theoretical point of view and experimentally verified through a set of polarimetric measurements. We show how the approach presented here can be useful in easily synthetizing depolarizing samples with controlled depolarizing features, just by properly combining low-cost fully polarizing elements (such as linear retarders or polarizers).

29 citations

Journal ArticleDOI
14 Mar 2019-PLOS ONE
TL;DR: The potential of polarimetric measurements in the study of plants is highlighted, suggesting they can be applied to the characterization of plants, plant taxonomy, water stress in plants, and other botanical studies.
Abstract: Optical methods, as fluorescence microscopy or hyperspectral imaging, are commonly used for plants visualization and characterization. Another powerful collection of optical techniques is the so-called polarimetry, widely used to enhance image contrast in multiple applications. In the botanical applications framework, in spite of some works have already highlighted the depolarizing print that plant structures left on input polarized beams, the potential of polarimetric methods has not been properly exploited. In fact, among the few works dealing with polarization and plants, most of them study light scattered by plants using the Degree of Polarization (DoP) indicator. Other more powerful depolarization metrics are nowadays neglected. In this context, we highlight the potential of different depolarization metrics obtained using the Mueller matrix (MM) measurement: the Depolarization Index and the Indices of Polarimetric Purity. We perform a qualitative and quantitative comparison between DoP- and MM-based images by studying a particular plant, the Hedera maroccana. We show how Mueller-based metrics are generally more suitable in terms of contrast than DoP-based measurements. The potential of polarimetric measurements in the study of plants is highlighted in this work, suggesting they can be applied to the characterization of plants, plant taxonomy, water stress in plants, and other botanical studies.

29 citations

Journal ArticleDOI
TL;DR: Using the measured Mueller matrix of a sample, a widespread number of PG configurations can be evaluated just from analytical expressions based on the MM coefficients, which shows the interest of controlling the helicity of the states of polarization used for PG-based metrology.
Abstract: We present mathematical formulas generalizing polarization gating (PG) techniques. PG refers to a collection of imaging methods based on the combination of different controlled polarization channels. In particular, we show how using the measured Mueller matrix (MM) of a sample, a widespread number of PG configurations can be evaluated just from analytical expressions based on the MM coefficients. We also show the interest of controlling the helicity of the states of polarization used for PG-based metrology, as this parameter has an impact in the image contrast of samples. In addition, we highlight the interest of combining PG techniques with tools of data analysis related to the MM formalism, such as the well-known MM decompositions. The method discussed in this work is illustrated with the results of polarimetric measurements done on artificial phantoms and real ex-vivo tissues.

22 citations

Journal ArticleDOI
TL;DR: The results illustrate the way to determine the set of depolarization metrics which optimizes tissue classification efficiencies, and show the interest of the method which is general, and which can be applied to study multiple types of biological samples, including of course human tissues.
Abstract: Classification of tissues is an important problem in biomedicine. An efficient tissue classification protocol allows, for instance, the guided-recognition of structures through treated images or discriminating between healthy and unhealthy regions (e.g., early detection of cancer). In this framework, we study the potential of some polarimetric metrics, the so-called depolarization spaces, for the classification of biological tissues. The analysis is performed using 120 biological ex vivo samples of three different tissues types. Based on these data collection, we provide for the first time a comparison between these depolarization spaces, as well as with most commonly used depolarization metrics, in terms of biological samples discrimination. The results illustrate the way to determine the set of depolarization metrics which optimizes tissue classification efficiencies. In that sense, the results show the interest of the method which is general, and which can be applied to study multiple types of biological samples, including of course human tissues. The latter can be useful for instance, to improve and to boost applications related to optical biopsy.

13 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

01 Jan 2016
TL;DR: In this paper, the authors present the principles of optics electromagnetic theory of propagation interference and diffraction of light, which can be used to find a good book with a cup of coffee in the afternoon, instead of facing with some infectious bugs inside their computer.
Abstract: Thank you for reading principles of optics electromagnetic theory of propagation interference and diffraction of light. As you may know, people have search hundreds times for their favorite novels like this principles of optics electromagnetic theory of propagation interference and diffraction of light, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their computer.

2,213 citations

Journal ArticleDOI
TL;DR: This volume, which is fourth of a series, comprises authoritative chapters dealing with determination of body fluid volumes and an introduction to flame photometry and a review of recentstudies by M. Otis.
Abstract: This volume, which is fourth of a series, comprises authoritative chapters dealing with determination of body fluid volumes by S. Chien and M. I. Gregersen, techniques of vascular perfusion by E. M. Renkin, the oxygen cathode by P. W. Davies, some physical techniques used in the study of external respiration by A. B. Otis, an introduction to flame photometry and a review of recentstudies by M. Margoshes, and ultrasound— analysis and experimental methods in biological research—by W. J. Fry and F. Dunn. The material is presented at a level suitable for graduate students or for professional research people who are entering a new field of investigation. Suitable diagrams, tables, and essential equations are presented and fully explained. The references listed at the end of each chapter are up to date and sufficiently numerous to serve the purpose. The authors and editor are to be congratulated upon their success in boiling

50 citations

Journal ArticleDOI
Tongyu Huang1, Ruoyu Meng1, Ji Qi, Yudi Liu1, Xingjian Wang1, Yan Chen1, Ran Liao1, Hui Ma1 
TL;DR: The experimental results show that a dual division of focal plane (DoFP) polarimeters-based full Mueller matrix microscope has the potential to be a powerful tool for probing dynamic processes in living cells in future studies.
Abstract: In this Letter, we report a dual division of focal plane (DoFP) polarimeters-based full Mueller matrix microscope (DoFPs-MMM) for fast polarization imaging. Both acquisition speed and measurement accuracy are improved compared with those of a Mueller matrix microscope based on dual rotating retarders. Then, the system is applied to probe the polarization properties of a red blood cells smear. The experimental results show that a DoFPs-MMM has the potential to be a powerful tool for probing dynamic processes in living cells in future studies.

40 citations

Journal ArticleDOI
TL;DR: The interest of using the indices of polarimetric purity (IPPs) to the inspection of biological tissues is highlighted and a pseudo-colored encoding of the IPP information that leads to an improved visualization of samples is proposed that opens the possibility of tailored adjustment of tissues contrast by using customized pseudo- colored images.
Abstract: We highlight the interest of using the indices of polarimetric purity (IPPs) to the inspection of biological tissues. The IPPs were recently proposed in the literature and they result in a further synthetization of the depolarizing properties of samples. Compared with standard polarimetric images of biological samples, IPP-based images lead to larger image contrast of some biological structures and to a further physical interpretation of the depolarizing mechanisms inherent to the samples. In addition, unlike other methods, their calculation do not require advanced algebraic operations (as is the case of polar decompositions), and they result in 3 indicators of easy implementation. We also propose a pseudo-colored encoding of the IPP information that leads to an improved visualization of samples. This last technique opens the possibility of tailored adjustment of tissues contrast by using customized pseudo-colored images. The potential of the IPP approach is experimentally highlighted along the manuscript by studying 3 different ex-vivo samples. A significant image contrast enhancement is obtained by using the IPP-based methods, compared to standard polarimetric images.

36 citations