this work introduces a new compression scheme for point sets. this scheme relies on an adaptive binary space partition (BSP) which takes into account the geometric structure of the point set. this choice introduces ge...
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ISBN:
(纸本)0769526861
this work introduces a new compression scheme for point sets. this scheme relies on an adaptive binary space partition (BSP) which takes into account the geometric structure of the point set. this choice introduces geometrical rather than combinatorial information in the compression scheme. In order to effectively improve the final compression ratio, this partition is encoded in a progressive manner decreasing the number of bits used for the quantisation at each subdivision. this strategy distributes the extra cost of the geometry encoding onto the maximal number of points, compressing in average 15% more than previous techniques.
Often, it is necessary to evaluate the mid-secretory endometrium appearance in Gynecology. For this purpose, hysteroscopic videos have been used, and are of fundamental importance nowadays for diagnosis/prognosis of s...
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Often, it is necessary to evaluate the mid-secretory endometrium appearance in Gynecology. For this purpose, hysteroscopic videos have been used, and are of fundamental importance nowadays for diagnosis/prognosis of several uterine pathologies. these videos are continuous (non-interrupted) video sequences, usually recorded in full. However, only a few segments of the recorded videos are relevant for diagnosis/prognosis, and need to be evaluated and referenced later. this paper proposes a new technique to identify clinically relevant segments in diagnostic hysteroscopy videos and, consequently, to find images that present the best view of the endometrium details (e.g. glandular openings and vascularization). Our method produce a rich and compact video summary which supports fast video browsing. this method is based on an extension of known properties of the singular value decomposition (SVD), and it is adaptive, in the sense that it minimizes the need of parameter adjustments. Our preliminary experimental results indicate that our method produces compact video summaries containing a selection of clinically relevant video segments. these experimental results were validated by specialists. (c) 2006 Elsevier B.V. All rights reserved.
the study of handwritten words is tied to the development of recognition methods to be used in real-world applications involving handwritten words, such as bank checks, postal envelopes, and handwritten texts, among o...
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the study of handwritten words is tied to the development of recognition methods to be used in real-world applications involving handwritten words, such as bank checks, postal envelopes, and handwritten texts, among others. In this work, the focus is handwritten words in the context of brazilian bank checks, specifically the months of the year, and no restrictions are placed on the types or styles of writing or the number of writers. A global feature set and two architectures of artificial neural networks (ANN) are evaluated for classification of the words. the objectives are to evaluate the performance of conventional and class-modular multiple-layer perceptron (MLP) architectures, to develop a rejection mechanism based on multiple thresholds, and to analyze the behavior of the feature set proposed in the two architectures. the experimental results demonstrate the superiority of the class-modular architecture over the conventional MLP architecture. A rejection mechanism with multiple thresholds demonstrates favorable performance in both architectures. the feature set analysis shows the importance of the structural primitives such as concavities and convexities, and perceptual primitives such as ascenders and descenders. the experimental results reveal a recognition rate of 81.75% without the rejection mechanism, and a reliability rate 91.52% with a rejection rate of 25.33%. (c) 2006 Elsevier B.V. All rights reserved.
this work presents the application of advanced analysis processes and datamining to images produced by scanning probe microscopy in polymers samplers. these techniques are applied to two specific problems: statistical...
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ISBN:
(纸本)0769513301
this work presents the application of advanced analysis processes and datamining to images produced by scanning probe microscopy in polymers samplers. these techniques are applied to two specific problems: statistical characterization of polydispersivity in films of poly (o-methoxyaniline) (POMA) and morphological analysis of substrates of polymers used to produce liquid crystals alignment.
Optical microscopic images, especially with a nonconfocal microscope, are fundamentally limited because the optical transfer function (the Fourier transform of the point-spread function) is zero over a region of the s...
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ISBN:
(纸本)9780769529967
Optical microscopic images, especially with a nonconfocal microscope, are fundamentally limited because the optical transfer function (the Fourier transform of the point-spread function) is zero over a region of the spatial-frequency domain. Iterative algorithms were developed for the restoration and extrapolation of diffraction-limited imagery. In this paper we present the effectiveness of an iterative method based on the Richardson-Lucy algorithm for image restoration and a simultaneous modified version of Gerchberg-Papoulis method to extrapolate the spectrum and control the noise amplification. Good convergence stabilization results were achieved and also good numerical results were observed.
this paper introduces a methodology for adding color to grayscale images in a way that is completely automatic. Towards this goal, we build on a technique that was recently developed to transfer colors from a user-sel...
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this paper introduces a methodology for adding color to grayscale images in a way that is completely automatic. Towards this goal, we build on a technique that was recently developed to transfer colors from a user-selected source image to a target grayscale image. More specifically, in order to eliminate the need for manual selection of the source image, we use content-based image retrieval methods to find suitable source images in an image database. To assess the merit of our methodology, we performed a survey where volunteers were asked to rate the plausibility of the colorings generated automatically for grayscale images. In most cases, automatically-colored images were rated either as totally plausible or as mostly plausible. (c) 2006 Elsevier B.V. All rights reserved.
We present a CAD system for skeletal age assessment based on Tanner-Whitehouse method. Using digital X-ray left hand images, maturity indicators are searched by means of a interactive process. Results indicate that th...
ISBN:
(纸本)0769513301
We present a CAD system for skeletal age assessment based on Tanner-Whitehouse method. Using digital X-ray left hand images, maturity indicators are searched by means of a interactive process. Results indicate that this approach is useful to speed up the analysis of growth disorders.
We describe ongoing research on the development of a functional system for diagnosing and measuring ocular refractive errors in the human eye (astigmatism, hypermetropia and myopia) by automatically analyzing images o...
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ISBN:
(纸本)076951846X
We describe ongoing research on the development of a functional system for diagnosing and measuring ocular refractive errors in the human eye (astigmatism, hypermetropia and myopia) by automatically analyzing images of the human ocular globe acquired withthe Hartmann-Shack (H-S) technique. H-S images are to be input into a system capable of recognizing the presence of a refractive error and outputting a measurement of such an error. Because the H-S technique provides images rich with information on the human eye, we believe this system may provide a framework that can be extended to get additional information on the health of imaged ocular globes.
this paper proposes a new rotation-invariant and scale-invariant representation for texture image retrieval based on Steerable Pyramid Decomposition. By calculating the mean and standard deviation of decomposed image ...
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ISBN:
(纸本)9780769529967
this paper proposes a new rotation-invariant and scale-invariant representation for texture image retrieval based on Steerable Pyramid Decomposition. By calculating the mean and standard deviation of decomposed image subbands, the texture feature vectors are extracted. To obtain rotation or scale invariance, the feature elements are aligned by considering either the dominant orientation or dominant scale of the input textures. Experiments were conducted on the Brodatz database aiming to compare our approach to the conventional Steerable Pyramid Decomposition, and a recent proposal for texture characterization based on Gabor Wavelets with regard to their retrieval effectiveness. Results demonstrate the superiority of the proposed method in rotated and scaled image datasets.
作者：
Clua, EWGDreux, MFeijó, BICAD
Department of Computer Science PUC - Rio Brazil ICAD
Department of Mechanical Engineering PUC - Rio Brazil
In order to obtain models of complex virtual environments, there are many solutions that make use of image-based rendering techniques. When using a set of images to represent an element in space as a billboard, there ...
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ISBN:
(纸本)0769513301
In order to obtain models of complex virtual environments, there are many solutions that make use of image-based rendering techniques. When using a set of images to represent an element in space as a billboard, there are some problems related withthe shading calculations, once these elements are just planes in space. this article presents a new approach for shading objects represented by images, which divides the problem into two parts: the shading maps generation for an object with specific set of lights in the environment and real-time shading simulation for a specific observer point of view and object location.
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