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Enhanced multi-level filter algorithm and its VLSI architecture

INTERNATIONAL JOURNAL OF ELECTRONICS 2007年第2期94卷 157-169页

作者： Zhaoqing, Z. Chaoyang, C. Jianwei, S. Liqiang, J. Tianxu, Z. Huazhong Univ Sci & Technol Inst Pattern Recognit & Artificial Intelligence State Key Lab Image Proc & Intelligent Control Wuhan 430074 Hubei Peoples R China

This paper presents an enhanced multi-level filter algorithm and its Very Large Scale Integration (VLSI) architecture for infrared image processing. The modified multi-level filter algorithm resolves the splitting targets problem using Gaussian pyramid processing. Owning three filtering paths, the proposed VLSI architecture of the filter can simultaneously enhance small targets with different sizes in infrared images. Some design techniques in implementing hardwired multiplication, subsample and asynchronous FIFO have been presented. This VLSI architecture has been implemented using Semiconductor Manufacturing International Corporation (SMIC) 0.35 mu m 4-layer CMOS technology. The simulation results show that it not only effectively suppresses background, eliminates noise and enhances small targets in an infrared image comparing with other small target detective methods, but also meets infrared image real-time processing requirements (5M similar to 10M pixels/s). The implemented filter chip consists of 60,284 gates and 8 K Static Random Access Memory (SRAM), operates at 50 MHz.

关键词： VLSI infrared image processing filters

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On-line estimation of image jacobian matrix by improved broyden's method in uncalibrated visual servoing

On-line estimation of image jacobian matrix by improved broy...

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Conference on Pattern Recognition and Computer Vision

作者： Zeng, Xiangjin Huang, Xinhan Wang, Min Huazhong Univ Sci & Technol Dept Control Sci & Engn Key Lab Image Proc & Intelligent Control Wuhan 430074 Peoples R China

ISBN: (纸本)9780819469526

A novel improved broyden's method has been presented to estimate image jacobian matrix for uncalibrated visual servoing. In this paper, we apply chebyshev polynomial as a cost function to approximate best value. Compared with recursive least square (RLS) algorithm which is restricted by the prior knowledge for obtaining some performances, chebyshev polynomial algorithm has a great adaptability to estimate jacobian parameter, even without the prior knowledge. A microscopic image jacobian model has been developed for the four degree-of-freedom micromanipulator in our microassembly system. The performance has been confirmed by simulations and experiments.

关键词： image jacobian matrix broyden' method chebyshev RLS uncalibrated visual servoing

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Contour detection based on contextual influences

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image AND VISION COMPUTING 2007年第8期25卷 1282-1290页

作者： Tang, Qiling Sang, Nong Zhang, Tianxu Huazhong Univ Sci & Technol Inst Pattern Recognit & Artificial Intelligence Wuhan 430074 Peoples R China Minist Educ Image Proc & Intelligent Control Key Lab Wuhan 430074 Peoples R China

A contour detection model, inspired by the behavior of the primary visual cortex, is presented. The response of a central stimulus in the receptive field is affected by the presence of surrounding stimuli - for some stimulus conditions, the response is suppressed and for other conditions the response is enhanced. The visual mechanisms of contextual influences are utilized to extract "coherent" configurations. This is mainly due to the following two reasons: (1) on the one hand, a smooth contour can yield collinear excitation, which highlights smooth contours from irregularly textured surround;(2) on the other hand, similar orientation textures receive iso-orientation surround suppression and region boundary is subjected to the less inhibition, which makes boundary more salient for perceptual pop-out. Accordingly, smooth contours progressively stand out from their surround and at the same time textures are gradually suppressed by their surround through dynamic fine-tuning of contextual information. The proposed method which distinguishes between contours and texture edges is more effective for contour-based object recognition tasks. Initial experiments show that the model can be successfully applied to contour detection. Especially, when object contours are lumped together with unwantedly cluttered surround, the advantage of our approach is more prominent. This study provides a biological scheme for contour detection in computer vision. (c) 2006 Elsevier B.V. All rights reserved.

关键词： contour detection contextual influences visual mechanisms suppression enhancement

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Parameter design method of stator flux estimation for direct torque control using ADRC

Parameter design method of stator flux estimation for direct...

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2nd IEEE Conference on Industrial Electronics and Applications (ICIEA 2007)

作者： Hu, Chanjuan Wani, Yubin Jiang, Xianglong Luo, Hui Deng, Guozhang Qin, Yi Wan, Shuyun Huazhong Univ Sci & Technol Dept Control Sci & Engn Wuhan 430074 Hubei Peoples R China Key Lab Image Processing & Intelligent Control Wuhan 430074 Peoples R China HuangGang Politech Coll Wuhan 430074 Peoples R China

ISBN: (纸本)9781424407361

In traditional Direct Torque control (DTC), speed regulator is widely based on conventional Proportional Integral Derivative (PID) controller, which has to depend on precise math model of the subject. However, PID cannot easily achieve swift response, small overshooting and fine speed control precision especially in low speed range. This paper introduces a nonlinear control tcchnology-Auto Disturbance Rejection controller (ADRC) into DTC to improve the speed adaptation capability and robustness, and a parameter design method of stator flux estimation is proposed. The simulation results prove the system has good control performance.

关键词： Torque control

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Face recognition under variable lighting using local qualitative representations

Face recognition under variable lighting using local qualita...

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MIPPR 2007: Pattern Recognition and Computer Vision

作者： Zhang, Yi Chu, Ying Mou, Xingang Zhang, Guilin State Education Commission Key Laboratory for Image Processing and Intelligent Control Institute for Pattern Recognition and Artificial Intelligence Huazhong University of Science and Technology Wuhan 430074 China

ISBN: (纸本)9780819469526

In this paper, a face recognition method using local qualitative representations is proposed to solve the problem of face recognition in varying lighting. Based on the observation that the ordinal relationship between the average brightness of image regions pair is invariant under lighting changes, Local Binary Mapping is defined as an illumination invariant for face recognition based on Local Binary Pattern descriptor, which extracts the local variance features of an image. For the 'symbol' feature vector, hamming distance is used as similarity measurement. It has been proved that the proposed method can provide the accuracy of 100 percent for subset 2, 3, 4 and 98.89 percent for subset 5 of the Yale facial database B when all images in subset 1 are used as gallery.

关键词： Face recognition

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Knowledge-based adaptive thresholding segmentation of digital subtraction angiography images

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image AND VISION COMPUTING 2007年第8期25卷 1263-1270页

作者： Sang, Nong Li, Heng Peng, Weixue Zhang, Tianxu Huazhong Univ Sci & Technol Inst Pattern Recognit & Artificial Intelligence Wuhan 430074 Peoples R China Huazhong Univ Sci & Technol Minist Educ Key Lab Image Proc & Intelligent Control Wuhan 430074 Peoples R China

Vessel segmentation is the base of three dimensional reconstruction on digital subtraction angiography (DSA) images. In this paper we propose two simple but efficient methods of vessel segmentation for DSA images. The original DSA image is divided into several appropriate subimages according to a prior knowledge of the diameter of vessels. We introduce the vessels existence measure to determine whether each subimage contains vessels and then choose an optimal threshold, respectively, for every subimage previously determined to contain vessels. Finally, an overall binarization of the original image is achieved by combining the thresholded subimages. Experiments are implemented on cerebral and hepatic DSA images. The results demonstrate that our proposed methods yield better binary results than global thresholding methods and some other local thresholding methods do. (c) 2006 Elsevier B.V. All rights reserved.

关键词： digital subtraction angiography adaptive threshold the busyness

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Color-based scale-invariant feature detection applied in robot vision

Color-based scale-invariant feature detection applied in rob...

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Symposium on Remote Sensing and GIS Data processing and Applications;and Innovative Multispectral Technology and Applications

作者： Gao, Jian Huang, Xinhan Peng, Gang Wang, Min Li, Xinde Huazhong Univ Sci & Technol Dept Control Sci & Engn Key Lab Minist Educ Image Proc & Intelligent Cont Wuhan 430074 Peoples R China

ISBN: (纸本)9780819469540

The scale-invariant feature detecting methods always require a lot of computation yet sometimes still fail to meet the real-time demands in robot vision fields. To solve the problem, a quick method for detecting interest points is presented. To decrease the computation time, the detector selects as interest points those whose scale normalized Laplacian values are the local extrema in the nonholonomic pyramid scale space. The descriptor is built with several subregions, whose width is proportional to the scale factor, and the coordinates of the descriptor are rotated in relation to the interest point orientation just like the SIFT descriptor. The eigenvector is computed in the original color image and the mean values of the normalized color g and b in each subregion are chosen to be the factors of the eigenvector. Compared with the SIFT descriptor, this descriptor's dimension has been reduced evidently, which can simplify the point matching process. The performance of the method is analyzed in theory in this paper and the experimental results have certified its validity too.

关键词： robot vision feature detection scale-invariant color information

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New coarse region segmentation used in computer-aided diagnosis of liver cancer from ultrasound images

New coarse region segmentation used in computer-aided diagno...

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Conference on Medical Imaging, Parallel processing of images, and Optimization Techniques

作者： Huang, Xiaoyue Ding, Mingyue Xu, Tiantian Zhang, Songgeng Huazhong Univ Sci & Technol Inst Pattern Recognit & Artificial Intelligence State Key Lab Image Proc & Intelligent Control Wuhan 430074 Hubei Peoples R China HUST Dept Biomed Engn State Key Lab Image Proc & Intelligent Control Wuhan Peoples R China Beijing Tsinghua R & D Ind Inst Beijing 100085 Peoples R China

ISBN: (纸本)9780819469533

In this paper a coarse region segmentation of liver cancer in ultrasound images is introduced. The reason employing coarse region segmentation is to reflect the inhomogeneous distribution of the image gray levels and provide the features such as the distribution, shape and size of the suspect region of liver cancer. Then combine with the prior knowledge we can divide the image into three different classes, which the results of the analysis of the region's location can be used by a classifier in a multilayer classifier. Furthermore, the result of the coarse region segmentation will support the texture analysis for further classification. The segmentation is based on watershed algorithm in order to receive an integrated region and two processing techniques are adopted to avoid the over segmentation of watershed algorithm.

关键词： segmentation liver cancer computer-aided diagnosis image processing watershed

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image fusion algorithm using nonsubsampled contourlet transform

Image fusion algorithm using nonsubsampled contourlet transf...

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MIPPR 2007: Multispectral image processing

作者： Yang, Xiao Zhiguo, Cao Kai, Wang Zhengxiang, Xu Institute of Pattern Recognition and Artificial Intelligence State Education Commission Key Laboratory for Image Processing and Intelligent Control Huazhong Uni. of Sci. and Tech. Wuhan 430074 China

ISBN: (纸本)9780819469519

In this paper, a pixel-level image fusion algorithm based on Nonsubsampled Contourlet Transform (NSCT) has been proposed. Compared with Contourlet Transform, NSCT is redundant, shift-invariant and more suitable for image fusion. Each image from different sensors could be decomposed into a low frequency image and a series of high frequency images of different directions by multi-sacle NSCT. For low and high frequency images, they are fused based on local-contrast enhancement and definition respectively. Finally, fused image is reconstructed from low and high frequency fused images. Experiment demonstrates that NSCT could preserve edge significantly and the fusion rule based on region segmentation performances well in local-contrast enhancement.

关键词： image fusion

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3D ultrasound reconstruction based on rotational scanning coping with calibration uncertainty

3D ultrasound reconstruction based on rotational scanning co...

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Medical Imaging 2007 Conference

作者： Luo, Xiaoan Ding, Mingyue Zhou, Chenping Cai, Chao Qiu, Wu Zhou, Hua Huazhong Univ Sci & Technol Inst Pattern Recognit & Artificial Intelligence Image Proc & Intelligent Control Key Lab Minist Educ Wuhan 430074 Peoples R China

ISBN: (纸本)9780819466273

To obtain 3D ultrasound image, traditionally, a ID ultrasound transducer and an orientation system are used to get a series of 2D images and their positions. From these 2D images and position information, a 3D image is reconstructed. In this paper, the accuracy of the 3D image is determined by the accuracy of the position information, furthermore it affects the result of the measure from the 3D image. When in rotational scanning mode, the reconstructed 3D image is sensitive to the calibration parameters, including the orientation difference as well as the offset between the central line of each 2D US image and the rotational axis. To address this type of effects, we developed a 3D reconstruction technique considering the calibration uncertainty by building a transformation model with a 360 degrees scanning, and an accurate 3D reconstruction with calibration uncertainty is achieved. The experiments with both synthetic and scanning phantom data demonstrated the feasibility of our approach.

关键词： 3D ultrasound calibration 3D US image reconstruction rotational scanning

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