This paper presents a perceptual organization based method for the representation and extraction of junction structures of edge segments from digital images. Perceptual Junctions (PJs) are higher-level view invariant ...
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ISBN:
(纸本)0769521274
This paper presents a perceptual organization based method for the representation and extraction of junction structures of edge segments from digital images. Perceptual Junctions (PJs) are higher-level view invariant feature entities, which are made up by intersected generic edge tokens including both linear and non-linear segments. The class of low-order PJs (LPJs) is the junctions defined by two connected segments, and detected directly by an edge tracking and partitioning algorithm. The class of high-order PJs (HPJs) is the junctions made up by more than two segments which are extended from LPJs by grouping additional segments from different edge traces. The method is robust since it mainly uses qualitative perceptual features. The computation is efficient because it is mainly involved in symbolic reasoning. The experimental results are provided.
A real-time probabilistic face tracking system using monocular vision is presented based on face target acquisition and subsequent particle filtering techniques. First, the face target acquistion and initialization st...
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ISBN:
(纸本)0769521274
A real-time probabilistic face tracking system using monocular vision is presented based on face target acquisition and subsequent particle filtering techniques. First, the face target acquistion and initialization stage used a skin color classification and statistical face model matching approach to find the face target. Subsequently, the particle filtering technique is used to track the state space of face movements. And finally, the optical flow information was used to find motion information for sample redistribution. The system places emphasis on the automatic face target initialization stage, which has been assumed to be solved or labeled manually in most other face tracking systems. Using a monocular USB camera on an Intel Pentium III 700 MHz laptop, the face detection and initialization stage is executed in less than 250 msec and the subsequent face tracking stage functions at 30 fps comfortably with 160×120-pixel resolution live videos.
Choosing unique and invariant features is the first important step in object tracking. In this paper, we present a method to find proper-sized and irregularly-shaped trackable features, the use of which can outperform...
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ISBN:
(纸本)0769521274
Choosing unique and invariant features is the first important step in object tracking. In this paper, we present a method to find proper-sized and irregularly-shaped trackable features, the use of which can outperform procedures using normal square features. The notion of confidence associated with each feature is introduced as the feature propagates. The use of confidence results in robust tracking even when occlusion is present. Based on the translational displacement of each feature, the affine motion of the object can be accurately estimated. This approach has been tested on a wide variety of video sequences and produces good tracking results.
In this paper we present a framework for the classification and segmentation of motion data. First, a representation of different two-dimensional motion categories is proposed. Secondly, a system to categorize and seg...
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ISBN:
(纸本)0769521274
In this paper we present a framework for the classification and segmentation of motion data. First, a representation of different two-dimensional motion categories is proposed. Secondly, a system to categorize and segment motion is presented based on hidden Markov models, commonly used in speech recognition. Input to the system consists of online pen stroke data which includes the x, y position and time of each point along the line. Using derived speed and direction information the system classifies and segments the input into particular categories of motion. The resulting categorical information may be then used to describe the scene, extrapolate events, or as a part of a gesture recognition system. Applications beyond pen-based input are discussed. This paper contributes to pen based motion recognition research in two ways. First, a classification is performed based on a continuous sequence of observations, rather then feature extraction. Secondly, pen motion is transformed into a translation and rotation invariant representation prior to classification.
A novel method of multi-modal nonlinear feature reduction is proposed for the recognition of handwritten numerals. In order to find an effective decision boundary, each class is divided into several clusters. Then the...
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ISBN:
(纸本)0769521274
A novel method of multi-modal nonlinear feature reduction is proposed for the recognition of handwritten numerals. In order to find an effective decision boundary, each class is divided into several clusters. Then the k-NN sorting algorithm is applied to each cluster to get the training data along the effective decision boundary. Optimal discriminant analysis is implemented by multimodal nonlinear mapping to generate a between-class scatter matrix, which requires less CPU time than other nonparametric approaches. Experiments demonstrated that our proposed method could achieve a high feature reduction without sacrificing much discriminant ability. As a result, this new method can reduce ANN training complexity and make the ANN classifier more reliable. Its feature dimensionality reduction outperforms the PCA and mono-modal nonparametric analysis.
A method is proposed to determine the average cellular geometry in high-resolution images of embryonic epithelia. The concept of a 'composite cell' is used to represent the average cell shape. This composite c...
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ISBN:
(纸本)0769521274
A method is proposed to determine the average cellular geometry in high-resolution images of embryonic epithelia. The concept of a 'composite cell' is used to represent the average cell shape. This composite cell can provide evidence of stresses present in the epithelia. A new adaptive contrast enhancement routine is applied to the input image first, followed by an iterative watershed segmentation. The composite cell is calculated from the segmentation results. Qualitative results show that this computationally inexpensive algorithm produces accurate results for a variety of image sizes, contrast levels, cell shapes and appearances.
The discrimination of textures is a significant aspect in segmenting SAR sea ice imagery. Texture features calculated from grey level co-occurring probabilities (GLCP) are well accepted and applied in the analysis of ...
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ISBN:
(纸本)0769521274
The discrimination of textures is a significant aspect in segmenting SAR sea ice imagery. Texture features calculated from grey level co-occurring probabilities (GLCP) are well accepted and applied in the analysis of many images. When calculating GLCPs, each co-occurring pixel pair within the image window is given a uniform weighting. Although a novel technique, co-occurring texture features have a tendency to misclassify and erode texture boundaries due to the large window sizes needed to capture meaningful statistics. A method is proposed whereby co-occurring pixel pairs closer to the center of the image window are assigned larger co-occurring probabilities according to a Gaussian distribution. By using a Gaussian weighting scheme to calculate the GLCPs, less significance is given to pixel pairs that are on the outlying regions of the window, which have a tendency to produce erroneous statistics as the image window overlaps a texture boundary. This method proves to preserve the edge strength between textures and provides better segmentation at the expense of computational complexity.
This paper proposes a new 2D segmentation method for MR shoulder images. Due to the significant length of the image sequences, we aim at minimizing the user intervention in the segmentation process. Our method integra...
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ISBN:
(纸本)0769521274
This paper proposes a new 2D segmentation method for MR shoulder images. Due to the significant length of the image sequences, we aim at minimizing the user intervention in the segmentation process. Our method integrates region and edge information in a coherent manner. In fact, the edge information is used in the definition of an adaptive similarity measure for iterative pixel aggregation. The seeds for the region growing process are defined automatically, which is essential for processing long image sequences with variable average brightness. Moreover, the proposed segmentation approach implements parallel region growing processes, and allows for dynamic region merging at successive iterations. To assess the performance of the proposed approach, we followed a standard methodology used for validating 2D segmentation, as well as a quantitative and qualitative evaluation of the 3D shoulder model reconstructed from the segmented image sequences.
We present a novel method for 3D shape recovery based on a combination of visual hull information and multi image stereo. We start from a coarse triangle mesh extracted from visual hull information. The mesh is then h...
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ISBN:
(纸本)0769521274
We present a novel method for 3D shape recovery based on a combination of visual hull information and multi image stereo. We start from a coarse triangle mesh extracted from visual hull information. The mesh is then hierarchically refined and its vertex positions are optimized based on multi image stereo information. This optimization procedure utilizes 3D graphics hardware to evaluate the quality of vertex positions, and takes both color consistency, and occlusion effects as well as silhouette information into account. By directly working on a triangle mesh we are able to obtain more spatial coherence than algorithms based entirely on point information, such as voxel-based methods. This allows us to deal with objects that have very little structure in some places, as well as small specular patches.
Nowadays, access to information requires to manage effectively multimedia databases, and among challenges offered to scientific community since last decades, multimedia retrieval techniques (particularly images retrie...
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ISBN:
(纸本)0769521274
Nowadays, access to information requires to manage effectively multimedia databases, and among challenges offered to scientific community since last decades, multimedia retrieval techniques (particularly images retrieval) are became an active research direction. Introduced to overcome the main drawbacks encountered by text-based images retrieval, which are the subjective and manual annotation of images, content based images retrieval (CBIR) systems index images according to low-level visual features such as color, texture, shape to retrieve similar images. However, despite the progress achieved in the content based image retrieval, in particular with the relevance feedback approach where the user refine the search via the specification of relevant or not relevant items, the current CBIR systems still have a major difficulty that it has yet to overcome: how to negotiate the "semantic gap"? This problem comes from the mismatch between their capabilities and the needs of users. In this paper, we address the problem of how relate low-level features to high level to bring out semantic concepts from images. Our aim is to combine content-based and metadata-based approaches for image retrieval from a user perspective to yield better results and overcome to the lacks of these techniques when they are taken separately. To represent the semantic content of images, we propose a model which takes account of the interaction between the user and the metadata. In particular, we model the semantic user' preference by analyzing its answers through the Relevance Feedback process. Furthermore, we introduce a new machine learning technique that modify the weights (i.e. relative importance) of metadata representing the semantic content of images.
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