Texture information is useful for image data browsing and retrieval. the goal of this paper is to present a texture classification system for remote sensing images addressed to the administration of great collections ...
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ISBN:
(纸本)076951846X
Texture information is useful for image data browsing and retrieval. the goal of this paper is to present a texture classification system for remote sensing images addressed to the administration of great collections of those images. the proposed classifier is a hybrid system composed by an unsupervised neural network and a supervised one. Starting from a small portion of the image (pattern) the system should recognize the most similar class to a pattern in a database as well as to identify the images that contain similar patterns. the texture feature vectors used to characterize the patterns are obtained from the images processed by a bank of Gabor Filters. Some experimental results using textures of the Brodatz album, multi-spectral and radar images are presented here.
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.
A new three-dimensional reconstruction technique is presented that uses an integer control parameter, denoted beta, to produce a family of models from a given set of planar cross-sections. Parameter beta supports mult...
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ISBN:
(纸本)076951846X
A new three-dimensional reconstruction technique is presented that uses an integer control parameter, denoted beta, to produce a family of models from a given set of planar cross-sections. Parameter beta supports multiple choices for solving the correspondence problem, i.e., the problem of deciding which regions from two consecutive cross-sections must be connected into a single component. thus, unlike current reconstruction methods, the beta-connection algorithm enables the consideration of multiple alternatives when establishing region correspondence. In addition to this flexibility, which is useful in creating models with complex topologies, the algorithm produces PL-manifolds and respects the re-sampling condition, thus providing an interesting reconstruction solution for many practical visualization and numerical simulation applications.
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 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 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 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.
In most of video shot boundary detection algorithms, proposed in the literature, several parameters and thresholds have to be set in order to achieve good results. In this paper, to get rid of parameters and threshold...
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ISBN:
(纸本)0769526861
In most of video shot boundary detection algorithms, proposed in the literature, several parameters and thresholds have to be set in order to achieve good results. In this paper, to get rid of parameters and thresholds, we explore a supervised classification method for video shot segmentation. We transform the temporal segmentation into a class categorization issue. Our approach defines a uniform framework for combining different kinds of features extracted from the video. Our method does not require any pre-processing step to compensate motion or post-processing filtering to eliminate false detected transitions. the experiments, following strictly the TRECVID 2002 competition protocol, provide very good results dealing with a large amount of features thanks to our kernel-based SVM classification method.
the choice of a color model is of great importance for many computer vision algorithms. However, there are many color models available;the inherent difficulty is how to automatically select a single color model or, al...
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ISBN:
(纸本)9780769529967
the choice of a color model is of great importance for many computer vision algorithms. However, there are many color models available;the inherent difficulty is how to automatically select a single color model or, alternatively, a subset of features from several color models producing the best result for a particular task. To achieve proper colors components selection, in this paper, it was proposed the use of wrapper method, a data mining approach, to obtain repeatability and distinctiveness in segmentation process. the result was compared with neural network method and yields good feature discrimination. the method was verified experimentally with 108 images from Amsterdam Library of Objects images (ALOI) and 10 aerial images with different photometric conditions. Furthermore, it has shown that the color model selection scheme provides a proper balance between color invariance (repeatability) and discriminative power (distinctiveness).
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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