The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform
Koichiro Deguchi - One of the best experts on this subject based on the ideXlab platform.
-
shape reconstruction from an endoscope image by shape from shading technique for a point light source at the projection center
Computer Vision and Image Understanding, 1997Co-Authors: Takayuki Okatani, Koichiro DeguchiAbstract:This paper presents a method for reconstructing the 3D shape of an object from its endoscope image based on image shading. The primary problem is that the endoscope has a light source near the object surface. Most of the conventional shape from shading methods assumed that the light source was distant from the object surface and simplified the analysis. To deal with the near light source, we use the configuration of the endoscope that the light source of the endoscope is well approximated by an imaginary point source at the projection center. In addition, we introduce a notion of equal distance contours of the object surface; by propagating the contours using the image shading, we reconstruct the object shape. This is an extension of the Kimmel?Bruckstein algorithm of shape from shading to the endoscope images. Experimental results for real medical endoscope images of the stomach wall show the feasibility of this method and also show its promising availability for morphological analyses of tumors on human inner organs.
Michael Elad - One of the best experts on this subject based on the ideXlab platform.
-
learning multiscale sparse representations for image and video restoration
Multiscale Modeling & Simulation, 2008Co-Authors: Julien Mairal, Guillermo Sapiro, Michael EladAbstract:This paper presents a framework for learning multiscale sparse representations of color images and video with overcomplete dictionaries. A single-scale K-SVD algorithm was introduced in [M. Aharon, M. Elad, and A. M. Bruckstein, IEEE Trans. Signal Process., 54 (2006), pp. 4311–4322], formulating sparse dictionary learning for grayscale image representation as an optimization problem, efficiently solved via orthogonal matching pursuit (OMP) and singular value decomposition (SVD). Following this work, we propose a multiscale learned representation, obtained by using an efficient quadtree decomposition of the learned dictionary and overlapping image patches. The proposed framework provides an alternative to predefined dictionaries such as wavelets and is shown to lead to state-of-the-art results in a number of image and video enhancement and restoration applications. This paper describes the proposed framework and accompanies it by numerous examples demonstrating its strength.
Takayuki Okatani - One of the best experts on this subject based on the ideXlab platform.
-
shape reconstruction from an endoscope image by shape from shading technique for a point light source at the projection center
Computer Vision and Image Understanding, 1997Co-Authors: Takayuki Okatani, Koichiro DeguchiAbstract:This paper presents a method for reconstructing the 3D shape of an object from its endoscope image based on image shading. The primary problem is that the endoscope has a light source near the object surface. Most of the conventional shape from shading methods assumed that the light source was distant from the object surface and simplified the analysis. To deal with the near light source, we use the configuration of the endoscope that the light source of the endoscope is well approximated by an imaginary point source at the projection center. In addition, we introduce a notion of equal distance contours of the object surface; by propagating the contours using the image shading, we reconstruct the object shape. This is an extension of the Kimmel?Bruckstein algorithm of shape from shading to the endoscope images. Experimental results for real medical endoscope images of the stomach wall show the feasibility of this method and also show its promising availability for morphological analyses of tumors on human inner organs.
Julien Mairal - One of the best experts on this subject based on the ideXlab platform.
-
learning multiscale sparse representations for image and video restoration
Multiscale Modeling & Simulation, 2008Co-Authors: Julien Mairal, Guillermo Sapiro, Michael EladAbstract:This paper presents a framework for learning multiscale sparse representations of color images and video with overcomplete dictionaries. A single-scale K-SVD algorithm was introduced in [M. Aharon, M. Elad, and A. M. Bruckstein, IEEE Trans. Signal Process., 54 (2006), pp. 4311–4322], formulating sparse dictionary learning for grayscale image representation as an optimization problem, efficiently solved via orthogonal matching pursuit (OMP) and singular value decomposition (SVD). Following this work, we propose a multiscale learned representation, obtained by using an efficient quadtree decomposition of the learned dictionary and overlapping image patches. The proposed framework provides an alternative to predefined dictionaries such as wavelets and is shown to lead to state-of-the-art results in a number of image and video enhancement and restoration applications. This paper describes the proposed framework and accompanies it by numerous examples demonstrating its strength.
Joachim Valentin - One of the best experts on this subject based on the ideXlab platform.
-
die maske des moses studien zur judischen hermeneutik by almut sh Bruckstein
Shofar, 2004Co-Authors: Joachim ValentinAbstract:Frankfurt a.M.: Philo Verlag, 2001. 200 pp. Euro 19.50. Bruckstein's work starts with a long and quite impressive footnote, in which she mentions a selection of several, mostly American, authors who have been exploring the Jewish literary genres Talmud and Midrash with the help of recently developed instruments of literary criticism and philosophy for nearly twenty years. Names like Susan A. Handelman, Michael Fishbane, Elliot Wolfson, and Daniel Boyarin, who are well known in the U.S., are mostly unknown in Germany. Moshe Idel's work isn't translated, and neither is Geoffrey Hartman's book Midrash and Literature. The Judaist and philosopher Almut Sh. Bruckstein (Jerusalem/Berlin) tries to introduce this U.S.-American debate to German speaking research. In five relatively independent chapters she asks the question: "in which way do figures of Jewish hermeneutics direct the philosophical work or start to convert it" (pp. 11f). Considering the separation between talmudic tradition and the liaison of Christian belief and pagan philosophy resulting in an anti-apocalyptic and anti-philosophic affect, it is astonishing that there has been a considerable philosophical output of Jewish textual tradition. But the basic methodological operation of this book is one of contemporary cultural studies rather than of philosophy. Considering so much contemporaneity, it must be allowed to bemoan a certain loss of ethical responsibility. The aim of the Wissenschaft des Judentums at the beginning of the 20(th) century had been, as Bruckstein correctly mentions, a "statement report about the meaning of the whole literature of Jewish tradition before the forum of ethical reason, which means before the forum of non-Jewish humankind -- in the public" (p. 19). Could this be said about cultural studies too? Nevertheless, the reader is rewarded with a well-informed guided tour through an "ocean" of explicitly philological texts which appeared on the background of the Wissenschaft des Judentums ["Topographie einer (zukunftigen) Philosophie der juedischen Hermeneutik," pp. 17-50]. Bruckstein shows how the exclusion of Jewish tradition -- the "other of European intellectual history" -- in Germany was sharpened by the absence of Jewish sages after 1945. In the tradition of E. Levinas and J. Derrida, she appeals for a model of "simultaneity of traditional narratives" to avoid new hierarchies. Under the title "Der unendliche Text. Midrasch in den Marginalien der Philosophie" (pp. 51-80), Brockstein links Jewish hermeneutics and a philosophy that criticizes identity and reveals a critical impetus of talmudic thinking in (post)modern times: "Jewish philosophy reflects the adventure of an endless text" (p. 62). The explanation of this -- possibly most central -- difference between Christian (incarnation) and Jewish (inlibration) thinking could simultaneously be the basis for a radical Jewish-Christian dialogue. In the third chapter ["Rosenzweig uber Heimkehr und Entfremdung. Exil als hermeneutischer Topos in judischer Uberlieferung," pp. 81-114] the author shows how Rosenzweig's philosophy of speech creates a space of his/her own for the interlocutor -- an approach which is based on the Jewish tradition to pass on even the minority opinions in the Talmud. …
