the article presents a method for the automatic extraction of the contents of passive and/or active cells in forms. the approach is based on the analysis and recognition of the types of intersection of the lines that ...
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the article presents a method for the automatic extraction of the contents of passive and/or active cells in forms. the approach is based on the analysis and recognition of the types of intersection of the lines that make up such cells. Very little a priori knowledge of the form is required. the performance of this approach depends on the correction module mechanisms for detection and correction of errors generated during the intersection identification phase. the potentialities and advantages of this approach are described and illustrated with tests carried out on different form bases.
the problem of detecting rectangular structures in images arises in many applications, from building extraction in aerial images to particle detection in cryo-electron microscopy. this paper proposes a new technique f...
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the problem of detecting rectangular structures in images arises in many applications, from building extraction in aerial images to particle detection in cryo-electron microscopy. this paper proposes a new technique for rectangle detection using a windowed Hough transform. Every pixel of the image is scanned, and a sliding window is used to compute the Hough transform of small regions of the image. Peaks of the Hough image (which correspond to line segments) are then extracted, and a rectangle is detected when four extracted peaks satisfy certain geometric conditions. Experimental results indicate that the proposed technique produced promising results for both synthetic and natural images.
We propose a new multiscale segmentation technique based on wavelet decompositions and watersheds. the wavelet transform is applied to the image, producing detail and approximation coefficients. the watershed is appli...
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We propose a new multiscale segmentation technique based on wavelet decompositions and watersheds. the wavelet transform is applied to the image, producing detail and approximation coefficients. the watershed is applied to the approximation image at a certain resolution 2/sup J/, and projected up to higher resolutions using the inverse wavelet transform. At lower resolutions, the segmentation captures large relevant objects, while at higher resolution more details are obtained. Since downsizing is inherent to the wavelet transform, watershed segmentation is applied to a smaller image, demanding less computational time. the proposed technique appears to be robust for noisy images, even when the amount of noise is very large.
the classical Douglas-Peucker line-simplification algorithm is recognized as the one that delivers the best perceptual representations of the original lines. It is used extensively for bothcomputergraphics and geogr...
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the classical Douglas-Peucker line-simplification algorithm is recognized as the one that delivers the best perceptual representations of the original lines. It is used extensively for bothcomputergraphics and geographic information systems. there are two variants of this algorithm, the original O(nm) method, where n denotes the number of input vertices and m the number of output segments, that works in any dimension, and the O(nlogn) one, which only works for simple 2D planar polylines. In the both variants, a self-intersecting simplified line may be yielded if the accepted approximation is not sufficiently fine. Based on star-shaped subsets, we present yet another O(mn) variant of Douglas-Peucker algorithm which preserves the nonself-intersection property for any predefined tolerance.
Deformable models are a powerful tool in bothcomputergraphics and computer vision. the description and implementation of the deformations have to be simultaneously flexible and powerful, otherwise the technique may ...
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Deformable models are a powerful tool in bothcomputergraphics and computer vision. the description and implementation of the deformations have to be simultaneously flexible and powerful, otherwise the technique may not satisfy the requirements of all the distinct applications. In this paper we introduce a new method for deformable model specification: deformable fields. Deformable fields are conceptually simple, lead to an easy implementation, and are suitable for adaptive models. We apply our new technique to describe an adaptive deformable face, and compare three different adaptation strategies. Additionally, we show how our technique is suitable to describe different individuals.
the signal quality of holographic memory is greatly lowered by the pixel mismatch between the charge-coupled device (CCD) and the reproduced image caused by image distortion. this paper discusses an approach to improv...
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the signal quality of holographic memory is greatly lowered by the pixel mismatch between the charge-coupled device (CCD) and the reproduced image caused by image distortion. this paper discusses an approach to improve the signal quality by using two step decoding method. By this method, first, distortion correction is done to improve the degree of pixel mismatch to obtain better signal to noise ratio (SNR). then, to eliminate errors such as noise that cannot be removed by distortion correction, soft decision Viterbi decoding using the newly defined reliability is used to correct errors. the effectiveness of this two step decoding method was tested by computer simulation, and its effect to improve SNR and reduce errors was confirmed.
GPUs have gained tremendous popularity in a broad range of application domains. these applications possess varying grains of parallelism and place high demands on compute resources - many times imposing real-time cons...
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the 3D reconstruction problem from a single endoscope image of a smooth object is studied in the context of the shape from shading methods and considering a single light source at the camera projection center. Based o...
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the 3D reconstruction problem from a single endoscope image of a smooth object is studied in the context of the shape from shading methods and considering a single light source at the camera projection center. Based on a curve expansion shape from shading algorithm, a spherical projection model for the endoscope camera and a dichromatic model for the surface reflectance, an approach to solve practical problems, namely the endoscope image distortion and the removal of the image specular reflection component, is presented. Results obtained from application of this approach to synthetic and real images are presented.
the estimation of multiple orientations in multidimensional signals is a strongly non-linear problem to which a two-step solution is here presented. First, the problem is linearized by introducing the so-called mixed-...
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the estimation of multiple orientations in multidimensional signals is a strongly non-linear problem to which a two-step solution is here presented. First, the problem is linearized by introducing the so-called mixed-orientation parameters as a unique, albeit implicit, descriptor of the orientations. Second, the non-linearities are decomposed such as to find the individual orientations. For two-dimensional signals, e.g., images, this decomposition step is solved by simply determining the roots of a polynomial. For multi-dimensional signals, the nD decomposition problem is solved by reducing it to a cascade of 2D decomposition problems. In this way, a full solution for the estimation of any number of orientations in any dimension is achieved for the first time
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