Real-time needle segmentation and tracking is very important in image-guided surgery, biopsy, and therapy. In this paper, we described an automated technique to provide real-time needle segmentation from a sequence of...
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ISBN:
(纸本)9780819469533
Real-time needle segmentation and tracking is very important in image-guided surgery, biopsy, and therapy. In this paper, we described an automated technique to provide real-time needle segmentation from a sequence of 2-D ultrasound images for the use of guidance of a needle to the target in soft tissues. The Hough transform is used to find straight lines or analytic curves in binary image. Hough transform is applied usually to binary images. Hence one needs to convert, initially, the gray level image to a binary one (through thresholding, edge detection, or thinning) in order to apply the HT. While in the process of binarization, some information about line segments in the image may be lost when an inappropriate threshold is used. Gray-Scale Hough Transform can detect the line without binarization. Unfortunately, its high computational cost often prevents it from being applied in real-time applications without the help of specially designed hardware. In this paper, we proposed a needle segmentation technique based on a real-time gray-scale Hough transform. It is composed of an improved Gray Hough Transformation and a coarse-fine search strategy. Furthermore, the RTGHT (Real-Time Gray-Scale Hough Transform) technique is evaluated by patient breast biopsy images. Experiments with patient breast biopsy ultrasound (US) image sequences showed that our approach can segment the biopsy needle in real time (i.e., less than 60 ms) with the angular rms error of about 1 degrees and the position rms error of about 0.5 nun. an affordable PC computer without the help of specially designed hardware.
An efficient method for facial feature location was proposed based on skin color segmentation and gray image symmetry transform. To reduce the influence of background and variable facial poses, the Blob analysis and e...
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An efficient method for facial feature location was proposed based on skin color segmentation and gray image symmetry transform. To reduce the influence of background and variable facial poses, the Blob analysis and ellipse fitting methods were successively applied to the image blobs detected by conventional skin color segmenting method. Invalid blobs were removed and candidate face regions were adjusted vertically. Then, mouth region was extracted from each candidate face region by segmenting hue image. Afterwards, the generalized symmetry transform (GST) of gray image was used to obtain candidate eyes and the real eyes were detected by combination optimization of the proposed cost function which was related to model of facial geometry and positions of eyes and mouth. Finally, other facial features such as chin and cheek could be precisely located. The test results show that the proposed approach is more effective and has better performance.
Instead of traditionally using a 3D physical model with many control points on it, a calibration plate with printed chess grid and movable along its normal direction is implemented to provide large area 3D control poi...
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Instead of traditionally using a 3D physical model with many control points on it, a calibration plate with printed chess grid and movable along its normal direction is implemented to provide large area 3D control points with variable Z values. Experiments show that the approach presented is effective for reconstructing 3D color objects in computer vision system.
In this paper, a new genetic algorithm for solving multi-constrained optimization problems based on KS function is proposed. Firstly, utilizing the agglomeration features of KS function, all constraints of optimizatio...
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In this paper, a new genetic algorithm for solving multi-constrained optimization problems based on KS function is proposed. Firstly, utilizing the agglomeration features of KS function, all constraints of optimization problems are agglomerated to only one constraint. Then, we use genetic algorithm to solve the optimization problem after the compression of constraints. Finally, the simulation results on benchmark functions show the efficiency of our algorithm.
An iterative blind deconvolution algorithm for degrade image is presented in this paper. The algorithm including two step, namely, the estimation of the point spread function of degrade image and the restoration using...
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ISBN:
(纸本)9780819469519
An iterative blind deconvolution algorithm for degrade image is presented in this paper. The algorithm including two step, namely, the estimation of the point spread function of degrade image and the restoration using estimated point spread function. Two different Hopfield neural networks are built for realize the two steps. An iterative procedure is used to control the restoration process. The simulation results indicate that the method is effective for blind deconvolution with high convergence speed.
An effective modeling method for nonlinear distributed parameter systems (DPSs) is critical for both physical system analysis and industrial engineering. In this paper, we propose a novel DPS modeling approach, in whi...
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An effective modeling method for nonlinear distributed parameter systems (DPSs) is critical for both physical system analysis and industrial engineering. In this paper, we propose a novel DPS modeling approach, in which a high-order nonlinear Volterra series is used to separate the time/space variables. With almost no additional computational complexity, the modeling accuracy is improved more than 20 times in average comparing with the traditional method. (c) 2006 Elsevier B.V. All rights reserved.
An innovative edge detection algorithm using the support value transform is presented in this *** on the support value transform, the multi scale support value images are extracted from the *** resolution of an image ...
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An innovative edge detection algorithm using the support value transform is presented in this *** on the support value transform, the multi scale support value images are extracted from the *** resolution of an image is directly related to the proper scale for edge detection, and the second level support value image is used to locate the edge positions by their zero *** experiments are carried out and sharp image edges are obtained from a variety of sample *** with many other existing methods, including LoG and Canny detectors, the proposed algorithm is superior to the LOG and Roberts approach.
The blind image restoration based on the nonlinear inverse heat diffusion equation and total variation model has been developed in the past decades. In this paper, a novel genetic algorithm by combining genetic algori...
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ISBN:
(纸本)9780819469540
The blind image restoration based on the nonlinear inverse heat diffusion equation and total variation model has been developed in the past decades. In this paper, a novel genetic algorithm by combining genetic algorithm with anisotropic diffusion technique is put forward to implement the super-resolution image restoration. In the procedure of mutation, we proposed a new genetic mutation operator based on anisotropic diffusion to guide the mutation. The solution space with the higher resolution is formed by the introduction of the new genetic mutation operator. The validity and robustness of our method was demonstrated by using aerial images.
In this article a new slice-based 3D prostate segmentation method based on a continuity constraint, implemented as an autoregressive (AR) model is described. In order to decrease the propagated segmentation error prod...
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In this article a new slice-based 3D prostate segmentation method based on a continuity constraint, implemented as an autoregressive (AR) model is described. In order to decrease the propagated segmentation error produced by the slice-based 3D segmentation method, a continuity constraint was imposed in the prostate segmentation algorithm. A 3D ultrasound image was segmented using the slice-based segmentation method. Then, a cross-sectional profile of the resulting contours was obtained by intersecting the 2D segmented contours with a coronal plane passing through the midpoint of the manually identified rotational axis, which is considered to be the approximate center of the prostate. On the coronal cross-sectional plane, these intersections form a set of radial lines directed from the center of the prostate. The lengths of these radial lines were smoothed using an AR model. Slice-based 3D segmentations were performed in the clockwise and in the anticlockwise directions, where clockwise and anticlockwise are defined with respect to the propagation directions on the coronal view. This resulted in two different segmentations for each 2D slice. For each pair of unmatched segments, in which the distance between the contour generated clockwise and that generated anticlockwise was greater than 4 mm, a method was used to select the optimal contour. Experiments performed using 3D prostate ultrasound images of nine patients demonstrated that the proposed method produced accurate 3D prostate boundaries without manual editing. The average distance between the proposed method and manual segmentation was 1.29 mm. The average intraobserver coefficient of variation (i.e., the standard deviation divided by the average volume) of the boundaries segmented by the proposed method was 1.6%. The average segmentation time of a 352 X 379 X 704 image on a Pentium IV 2.8 GHz PC was 10 s. (C) 2007 American Association of Physicists in Medicine.
Omnidirectional mobile manipulator, which is composed by a three DOF omnidirectional mobile platform and a mounted manipulator, can move in any direction at any time. By reason of the redundantly actuated mechanism, t...
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Omnidirectional mobile manipulator, which is composed by a three DOF omnidirectional mobile platform and a mounted manipulator, can move in any direction at any time. By reason of the redundantly actuated mechanism, the omnidirectional motion property of the mobile platform is similar to the parallel manipulator cooperatively manipulating objects, which admits internal force doing none contribution to the motion of the platform. Thus, the internal force should be controlled to reduce energy waste. Therefore, a stable PD controller is developed first for motion control of the integrated mobile manipulator system. Then, by treating the motion induced force as disturbance, a feed forward plus PI type force controller is addressed to regulate the internal force to zero. Finally, simulation results demonstrate the validity of the proposed approach.
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