this paper makes a rereading of two successful image segmentation approaches, the fuzzy connectedness (FC) and the watershed (WS) approaches, by analyzing both by means of the image Foresting Transform (IFT). this gra...
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ISBN:
(纸本)0769526861
this paper makes a rereading of two successful image segmentation approaches, the fuzzy connectedness (FC) and the watershed (WS) approaches, by analyzing both by means of the image Foresting Transform (IFT). this graph-based transform provides a sound framework for analyzing and implementing these methods. this paradigm allows to show the duality existing between the WS by IFT and the FC segmentation approaches. Both can be modeled by an optimal forest computation in a dual form (maximization of the similarities or minimization of the dissimilarities), the main difference being the input parameters: the weights associated to each arc of the graph representing the image. In the WS approach, such weights are based on the (possibly filtered) image gradient values whereas they are based on much more complex affinity values in the FC theory. An efficient algorithm for both FC and IFT-WS computation is proposed. Segmentation robustness issue is also discussed.
We present a parametric model for feather modeling in computergraphics. the model is based on Bezier curves and allows easy generation of many feather structures through manipulation of the parameters.
ISBN:
(纸本)0769513301
We present a parametric model for feather modeling in computergraphics. the model is based on Bezier curves and allows easy generation of many feather structures through manipulation of the parameters.
this paper describes the design and implementation of NISVAS, an application for interactive visualization of large three-dimensional datasets produced by scientific applications that was developed in Java/Java3D. Dat...
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ISBN:
(纸本)0769513301
this paper describes the design and implementation of NISVAS, an application for interactive visualization of large three-dimensional datasets produced by scientific applications that was developed in Java/Java3D. Data visualization with NISVAS maps dataset magnitudes into color, symbols and vectors. this paper presents the concepts and requirements for NISVAS graphical processing and user interface. the user interface is easy to use and learn, and supports different levels of user expertise. User reactions to NISVAS showed that all objectives were met, especially those relating to application performance and ease of use. Concluding remarks include directions for future development.
In this paper we address the problem of lane detection and lane tracking. A linear model is used to approximate lane boundaries in the first frame of a video sequence, using a combination of the edge distribution func...
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ISBN:
(纸本)0769522270
In this paper we address the problem of lane detection and lane tracking. A linear model is used to approximate lane boundaries in the first frame of a video sequence, using a combination of the edge distribution function and the Hough Transform. A new linear-parabolic model is used in the subsequent frames: the linear part of the model is used to fit the near vision field, while the parabolic model fits the far field. the proposed technique demands low computational power and memory requirements, and showed to be robust in the presence of noise, shadows, lack of lane painting and change of illumination conditions.
We present methods for synthesizing 3D shape features on subdivision surfaces using multiscale procedural techniques. Multiscale synthesis is a powerful approach for creating surfaces with different levels of detail. ...
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ISBN:
(纸本)0769513301
We present methods for synthesizing 3D shape features on subdivision surfaces using multiscale procedural techniques. Multiscale synthesis is a powerful approach for creating surfaces with different levels of detail. Our methods can also blend multiple example multiresolution surfaces, including procedurally-defined surfaces as well as captured models.
this paper suggests an hierarchical region based representation to implement detection of shapes in gray-scale images. the Max-Tree structure has demonstrated to be useful for this purpose, offering a semantic objects...
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ISBN:
(纸本)0769522270
this paper suggests an hierarchical region based representation to implement detection of shapes in gray-scale images. the Max-Tree structure has demonstrated to be useful for this purpose, offering a semantic objects vision of the image, therefore, reducing the number of elements to process in relation to the pixel based representation. In this way, a particular thresholding information, associated with a specific shape analysis, can be used to determine the segmentation or filtering of regions of interest with lesser computational effort. For to demonstrate this technique, a generic application of detection of lines is proposed using the distance transform approach on each connected component from the depth searching in the mentioned tree.
this paper describes the development of a vision-based, nighttime navigation support system for automotive vehicles driving in semi-structured environments. the focus is on automatic reduction of glare produced by hig...
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ISBN:
(纸本)0769522270
this paper describes the development of a vision-based, nighttime navigation support system for automotive vehicles driving in semi-structured environments. the focus is on automatic reduction of glare produced by high beams from incoming vehicles and on generation of virtual lanes that are overlaid on the image where actual road markings should exist. To accomplish these goals, we develop video-based robust techniques that produce enhanced road images in real-time. the proposed techniques are validated by experiments with real video streams, which demonstrates the system's performance and accuracy under real conditions.
this poster describes a technique for reconstructing tomographic images generated by a minitomograph scanner for soil science developed by Embrapa Agricultural Instrumentation using a parallel DSP architecture with an...
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ISBN:
(纸本)0769513301
this poster describes a technique for reconstructing tomographic images generated by a minitomograph scanner for soil science developed by Embrapa Agricultural Instrumentation using a parallel DSP architecture with an HEPC2E board from Hunt Engineering with two TMS320C40 processors from Texas Instruments. the software designed for visualization of bi-and tri-dimensional images uses Code Composer tool combined with Parallel C from 3L and Borland Builder C++. Reconstruction and interpolation tasks were distributed throughout the platform processors, using parallel algorithms in order to improve speed and processing power. the work resulted in an increase of about 15% in the system speed when compared withthat reached using a classical platform at 200 MHz.
Active contours approach is a very used family of techniques in image analysis. this work presents a comparative study between two active contour approaches for image segmentation. Level sets method and deformable con...
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ISBN:
(纸本)0769522270
Active contours approach is a very used family of techniques in image analysis. this work presents a comparative study between two active contour approaches for image segmentation. Level sets method and deformable contours under B-spline representation are compared these image segmentation methods have different features and are difficult to compare in terms of performance, accuracy and initialization conditions. Both are implemented and a way to calculate the approximation error is developed As a conclusion of this work a theoretical comparison and a comparative characterization of the approximation error for each method are presented.
Linear analysis of intensity level histograms is proposed as a method to determine the area fractions of homogeneous components of images. the area tractions are the coefficients of the respective histograms in the li...
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ISBN:
(纸本)0769520324
Linear analysis of intensity level histograms is proposed as a method to determine the area fractions of homogeneous components of images. the area tractions are the coefficients of the respective histograms in the linear combination that best fits the histogram of the entire image. this method can be applied whenever the components can be identified by their individual histograms which must be linearly independent. Its accuracy was tested for images of real surfaces that were edited to contain known fractions of the component, and it proved to be suitable for the analysis of images made of textured components that show large overlapping of their histograms.
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