Digital image interpolation techniques are frequently used to enlarge pictures, i.e. zooming in, and they are upon increasingly demand for developing product applications using digital still cameras. One common diffic...
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ISBN:
(纸本)076951846X
Digital image interpolation techniques are frequently used to enlarge pictures, i.e. zooming in, and they are upon increasingly demand for developing product applications using digital still cameras. One common difficulty with conventional interpolation techniques is that of preserving details, i.e. edges, and at the same time smoothing the data for not introducing spurious artifacts. A definitive solution to this is still an open issue, although there are working methods in the market, see e.g. Parker et. al. [6], Sakamoto et. al. [8] for recent surveys. In this paper we propose a locally adaptive edge-preserving algorithm for image interpolation, which deals withthis problem, and different than other methods shows how to compute local thresholds preserving edges and not destroying smoothness at the same time.
We present a model for geometric modeling and rendering of individual feathers for computergraphics purposes. the model represents the feather structure with a collection of parameterized Bezier curves. this parametr...
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ISBN:
(纸本)076951846X
We present a model for geometric modeling and rendering of individual feathers for computergraphics purposes. the model represents the feather structure with a collection of parameterized Bezier curves. this parametrization allows easy generation of the existent types of feather structures with biologically-motivated parameters. Once the feather structure is defined, the feathers can be rendered either in a non-photorealistic rendering style or using texture mapping to achieve a more natural look.
We introduce concepts and algorithms for control of visual motor commands and realistic simulation of basic abilities as visual servoing and perception for robotics simulation. the introduced tools can also be used in...
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ISBN:
(纸本)076951846X
We introduce concepts and algorithms for control of visual motor commands and realistic simulation of basic abilities as visual servoing and perception for robotics simulation. the introduced tools can also be used in a straightforward way to build computer animated devices as virtual agents, and avatars. We use the tools to build part of a humanoid (arms and head) robot, effectively named "C (a) over cap mbio". We will describe C (a) over cap mbio's design, providing an overview on the most used feature extraction techniques for perception, discussing implementation issues. We intend to show the usefulness of a simulated platform as an inexpensive alternative for testing and developing computer vision algorithms in real-time robotics applications and its possible extensions to computer animated agents and avatars.
this work presents a method to output the 3D structure of an urban area from only one aerial photo. the reconstruction is based on the inverse process done when a parallel projection is used to construct a two-dimensi...
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ISBN:
(纸本)076951846X
this work presents a method to output the 3D structure of an urban area from only one aerial photo. the reconstruction is based on the inverse process done when a parallel projection is used to construct a two-dimensional image from a three-dimensional object. A new algorithm for reconstruction is developed and implemented. It recovers depth information by identification of object height on the image plane. While the 3D-objects are reconstructed, their original texture is used for rendering, using control points defined by the user. Results show that when seen from the same capture angle, the virtual 3D scene and the original picture are exactly the same. In the virtual environment of this implementation, the user can visualize, visit and interact withthe structure of the 3D scenario. the spatial structure of the real world is recovered at real time;it is possible to see the 3D growing out of the 2D images.
this article presents a method for the segmentation of substructures based on exploratory factor analysis. In this approach, a set of high-dimensional shape-related variables is examined withthe purpose of finding cl...
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ISBN:
(纸本)076951846X
this article presents a method for the segmentation of substructures based on exploratory factor analysis. In this approach, a set of high-dimensional shape-related variables is examined withthe purpose of finding clusters with strong correlation. this clustering can potentially identify regions that have anatomic significance and thus lend insight to morphometric investigations. Methods: the information about regional shape is extracted by registering a reference image to a set of test images. Based on the displacement fields obtained from image registration, the amount of pointwise volume enlargement or reduction is computed and statistically analyzed withthe purpose of extracting a reduced set of common factors. Experiments: the effectiveness and robustness of the method is demonstrated in a study of the human corpus callosum anatomy, based on a sample of 84 right-handed normal controls. Results: the method is able to partition the structure into regions of interest that present correlated shape variation. the confidence of results is evaluated by analyzing the statistical fit of the model.
this work presents the necessary steps to obtain the quantitative parameters of a superficial drainage basin, using digital imageprocessing techniques such as segmentation and mathematical morphology.
ISBN:
(纸本)0769513301
this work presents the necessary steps to obtain the quantitative parameters of a superficial drainage basin, using digital imageprocessing techniques such as segmentation and mathematical morphology.
A tool created withthe aim of contributing to the teaching of imageprocessing techniques is presented. It allows the specification of filters in a simple and intuitive manner. Being a Java application, the system is...
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ISBN:
(纸本)0769513301
A tool created withthe aim of contributing to the teaching of imageprocessing techniques is presented. It allows the specification of filters in a simple and intuitive manner. Being a Java application, the system is portable and runs in many different environments.
the identification and classification of motion patterns in point trajectories has been an important issue in understanding and representing dynamic scenes. this paper proposes an unsupervised approach to identify coh...
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ISBN:
(纸本)9780769529967
the identification and classification of motion patterns in point trajectories has been an important issue in understanding and representing dynamic scenes. this paper proposes an unsupervised approach to identify coherent motion in video. Instead of producing a spatio-temporal segmentation of the raw data, the proposed method analyzes point trajectories along the video sequence to identify sets of points that move coherently. this new way of extracting motion information from videos potentially can be used in different areas of imageprocessing and computer vision.
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.
New advances in image based texture synthesis techniques allow the generation of arbitrarily sized textures based on a small sample. the generated textures are perceived as very similar to the given sample. One main d...
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ISBN:
(纸本)076951846X
New advances in image based texture synthesis techniques allow the generation of arbitrarily sized textures based on a small sample. the generated textures are perceived as very similar to the given sample. One main drawback of these techniques, however, is that the synthesized result cannot be locally controlled, that is, we are able to synthesize a larger version of the sample but without much variation. We present in this paper a technique which improves on current fast texture synthesis techniques by allowing local control over the result. By local control we mean a final texture that is still perceived as a whole but presents variations in size of the basic elements. Our solution generates the final texture from a small collection of the same sample at different resolutions, adequately interpolated. We illustrate our results with some examples, including natural textures such as animal coat patterns, which exhibit local variations that can be adequately captured by our algorithm.
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