This paper proposes a fast watershed algorithm derived from Meyer's simulated flooding based algorithm. Parallel processing adopted in conditional neighborhood comparisons for processing 3x3 pixels in one process ...
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ISBN:
(纸本)0780375742
This paper proposes a fast watershed algorithm derived from Meyer's simulated flooding based algorithm. Parallel processing adopted in conditional neighborhood comparisons for processing 3x3 pixels in one process leads to reduced computational complexity compared to Meyer's algorithm. The proposed algorithm has been implemented in Xilinx FPGA environment.
We present a robust region segmentation method based on a pseudo-distance map (PDM) that uses a watershed algorithm as a segmentation tool. The PDM is a regularized version of a Euclidean distance map (EDM) directly c...
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We present a robust region segmentation method based on a pseudo-distance map (PDM) that uses a watershed algorithm as a segmentation tool. The PDM is a regularized version of a Euclidean distance map (EDM) directly computed from the edge-strength function (ESF) of an input image without edge detection, which involves a thresholding operation. This unavoidably causes useful region boundary information loss from the original image. We show that applying the watershed algorithm to the PDM significantly reduces oversegmentation, and the final segmentation results obtained by a simple region-merging process are more accurate and meaningful and less sensitive to noise than those of the gradient-based or EDM-based methods. We also propose a simple and efficient region-merging criterion that considers both boundary strengths and inner intensities of regions to be merged. We tested and verified the robustness of our method with a variety of synthetic and real images. (C) 2004 SPIE and IST.
The purpose of this research was to present an image processing tool in order to provide ophthalmologists with assistance for diagnosis. This work has been developed to automate detection of the retinopathy of prematu...
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ISBN:
(纸本)0780385608
The purpose of this research was to present an image processing tool in order to provide ophthalmologists with assistance for diagnosis. This work has been developed to automate detection of the retinopathy of prematurity demarcation line or ridge pattern which is mainly used to determine the progress of the over production of blood vessels in the eye. The techniques presented in this paper consist of 4 main steps. First a local contrast enhancement has been applied and followed with a large filter based on Canny edge detection. Then an algorithm is applied based on an image processing technique called an early stopping watershed Finally, some region classification techniques are applied to the infant images. The watershed technique in this research is differs from the general watershed technique, because a gradient image is used as input data instead of gray scale or a thresholded image. Also in the algorithm used, the area, which has intensity equal to zero was automatically set as the initial seed points and stopped at particular level dependent on the variance of the whole image. The results obtained from application of the watershed algorithm were assessed for the possibility of being ROP ridge regions. The areas exhibiting a high probability of being an ROP ridge region were extracted using a region classification technique and exhibited to the clinician as a second decision.
A region-based method for facial tracking is proposed in this paper. In this method, the facial information of temporal motion and spatial luminance are fully utilized. The dominant motion of the tracked facial object...
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ISBN:
(纸本)0780386876
A region-based method for facial tracking is proposed in this paper. In this method, the facial information of temporal motion and spatial luminance are fully utilized. The dominant motion of the tracked facial object is computed. Using this result, the object template is warped to generate a prediction template. A method is proposed, which incorporates an artificial neural network (ANN), with back-propagation algorithm (BPA), to modify the prediction. A decision approach, with a threshold, is used to detect, if there is any change in the object of the successive frames. The accuracy of the result depends upon the number of nodes in the hidden layer and learning factor. The number of nodes in the hidden layer is 10, and the learning factor is 1. The performance of the algorithm, in reconstructing the tracked object, is about 96.5%, in terms of reduced time and quality of reconstruction.
To segment moving objects in head-and-shoulder image sequences, a new morphological image segmentation algorithm is proposed using a hierarchical structure based on a binary split algorithm. The split method is perfor...
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To segment moving objects in head-and-shoulder image sequences, a new morphological image segmentation algorithm is proposed using a hierarchical structure based on a binary split algorithm. The split method is performed using the combination of spatial and temporal similarities to reduce the residual errors between the original and segmented image. Spatial similarity is used to split those regions with the most different intensity values, while temporal similarity, based on the displacement vectors between two images, is used to split those regions with different motions. As a result, the proposed hierarchical segmentation method, based on a binary split algorithm, can increase the subjective image quality with only a small number of regions. Furthermore, a new contour simplification technique composed of three filtering steps is repeatedly applied to the segmented image, thereby eliminating any noisy contours of segmented regions. (C) 2003 Society of Photo-Optical Instrumentation Engineers.
We propose a new method for contour tracking in video. The inverted distance transform of the edge map is used as an edge indicator function for contour detection. Using the concept of topographical distance, the wate...
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We propose a new method for contour tracking in video. The inverted distance transform of the edge map is used as an edge indicator function for contour detection. Using the concept of topographical distance, the watershed segmentation can be formulated as a minimization. This new viewpoint gives a way to combine the results of the watershed algorithm on different surfaces. In particular, our algorithm determines the contour as a combination of the current edge map and the contour, predicted from the tracking result in the previous frame. We also show that the problem of background clutter can be relaxed by taking the object motion into account. The compensation with object motion allows to detect and remove spurious edges in background. The experimental results confirm the expected advantages of the proposed method over the existing approaches.
In this paper, we present a new approach for object boundary extraction, called the watersnake. It is a two-step snake algorithm whose energy functional is minimized by the dynamic programming method. It is more robus...
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In this paper, we present a new approach for object boundary extraction, called the watersnake. It is a two-step snake algorithm whose energy functional is minimized by the dynamic programming method. It is more robust to local minima because it finds the solution by searching the entire energy space. To reduce the complexity of the minimization process, the watershed transformation and a coarse-to-fine strategy are used. The new technique is compared to standard methods for accuracy in synthetic data and is applied to segmentation of white blood cells in bone marrow Images.
A fuzzy integral based region merging algorithm is presented to deal with the issue of oversegmentation due to the watershed transform. The algorithms integrates region and edge features together using a fuzzy logic b...
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ISBN:
(纸本)078037293X
A fuzzy integral based region merging algorithm is presented to deal with the issue of oversegmentation due to the watershed transform. The algorithms integrates region and edge features together using a fuzzy logic based fusion method. Firstly, preprocessing and watershed segmentation are performed on the image. Depending on the complexity of the image content the segmentation process may produce many more regions than what are really expected to exist in the image. To reduce the number of regions that results due to oversegmentation, a fusion process is applied to these regions recursively according to the principle of the maximum fuzzy integral. After transferring these features to memberships that reflect the degree that a given region to belong to its neighboring regions, an integration (fusion) scheme is used to compute a fuzzy integral based on which a decision is made with respect to the region merging. To evaluate the performance of the proposed approach it has been applied to real images such as MRI and natural images.
High-resolution in-vivo Magnetic Resonance Imaging (MRI) can be used effectively to determine variation in cartilage morphometry - a crucial parameter for assessment of osaeoarthritis, Segmentation of cartilage from s...
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ISBN:
(纸本)078036466X
High-resolution in-vivo Magnetic Resonance Imaging (MRI) can be used effectively to determine variation in cartilage morphometry - a crucial parameter for assessment of osaeoarthritis, Segmentation of cartilage from surrounding tissues is a necessary preliminary step to the quantitation process. In this in-vivo study we implement the immersion based watershed algorithm to develop a novel and reliable cartilage segmentation technique. The protocol has been successfully applied to determine morphometric differences among normal, mild and severe osteoarthritic patient populations.
This paper describes a method for partitioning 3D surface meshes into useful segments. The proposed method generalizes morphological watersheds, an image segmentation technique, to 3D surfaces. This surface segmentati...
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This paper describes a method for partitioning 3D surface meshes into useful segments. The proposed method generalizes morphological watersheds, an image segmentation technique, to 3D surfaces. This surface segmentation uses the total curvature of the surface as an indication of region boundaries. The surface is segmented into patches. where each patch has a relatively consistent curvature throughout, and is bounded by areas of higher, or drastically different, curvature, This algorithm has applications for a variety of important problems in visualization and geometrical modeling including 3D feature extraction, mesh reduction, texture mapping 3D surfaces, and computer aided design.
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