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浏览/检索结果: 共7条，第1-7条 帮助 已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 A Method for Improving the Detection Accuracy of the Spot Position of the Four-Quadrant Detector in a Free Space Optical Communication System 期刊论文 SENSORS, 2020, 卷号: 20, 期号: 24 作者:  Wang, Xuan;  Su, Xiuqin;  Liu, Guizhong;  Han, Junfeng;  Wang, Kaidi 收藏  |  浏览/下载：20/0  |  提交时间：2021/01/28 quadrant detectors  Gaussian spot  high background noise   Improved affine projection subband adaptive filter for high background noise environments 期刊论文 SIGNAL PROCESSING, 2017, 卷号: 137, 页码: 356-362 作者:  Zhao, Haiquan;  Zheng, Zongsheng;  Wang, Zhongyu;  Chen, Badong 收藏  |  浏览/下载：5/0  |  提交时间：2019/11/26 Affine projection subband adaptive filter  High background noise  Acoustic echo cancellation   Sparsity-enabled denoising method based on tunable Q-factor wavelet transform for bearing fault diagnosis 会议论文 作者:  Ding, Baoqing;  Tong, Chaowei;  Xin, Wei;  Wang, Shibin;  Chen, Xuefeng 收藏  |  浏览/下载：4/0  |  提交时间：2019/12/02 Background noise  Bearing fault diagnosis  Denoising methods  Fault feature extractions  High reliability  Oscillatory behaviors  Rolling Element Bearing  Simulated signals   A hybrid median filter for enhancing dim small point targets and its fast implementation (EI CONFERENCE) 会议论文 2011 International Conference on Multimedia and Signal Processing, CMSP 2011, May 14, 2011 - May 15, 2011, Guilin, Guangxi, China Yang Q. 收藏  |  浏览/下载：17/0  |  提交时间：2013/03/25 Weak stars and middle altitude orbit satellites or high altitude orbit satellites are presented as dim point targets in images of astronomical observation. They have low intensity and occupy few pixels in image. In most situations  the background of sky is always ununiform and there exists pulse noises. Thus results in targets submerging in background noises and low signal noise ratio (SNR). Median filter is an effective method for removing pulse noise. But it can blur image after modifying gray of non-noise pixels when image has low SNR. A hybrid median filter algorithm is proposed to process low SNR dim point targets image. The newly proposed method can suppress the pulse noises  also can increase target $SNR$ and does not add extra fake targets. The time complexity of median filter is O(N2)(N is the widow size) and is difficult to implement in hardware. For quasi real time application  a fast implementation of our hybrid median filter is proposed to reduce the time complexity to O(N). Experimental results show that the newly proposed algorithm is superior to ordinary median filter and fast median filter by comparing visual effect and performance. 2011 IEEE.   A matching algorithm on statistical properties of Harris corner (EI CONFERENCE) 会议论文 2011 International Conference on Information and Automation, ICIA 2011, June 6, 2011 - June 8, 2011, Shenzhen, China He B.; Ming Z.; Wei Y. 收藏  |  浏览/下载：18/0  |  提交时间：2013/03/25 The fundamental goal of target recognition and video tracking is to match target template with source image. Most matching methods are based on image intensity or multi-feature points. And the latter method is more popular for its high accuracy and small calculation. Image Registration Based on Feature Points focus on effective feature extraction of image points and paradigm. Harris corner in the image rotation  gray  noise and viewpoint change conditions  has an ideal match results  is more recent application of one feature point. This paper extract the Harris corner deviation and covariance firstly  experiments show that the two features exclusive  then applied them to image registration for the first time. A set of actual images have shown  this proposed method not only overcomes the complicated background  gray uneven distribution problems  but also pan and zoom the image has a good resistance. 2011 IEEE.   Research on tracking approach to low-flying weak small target near the sea (EI CONFERENCE) 会议论文 ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China Zhang S.-Y.; Liu W.-N.; Xue X.-C. 收藏  |  浏览/下载：24/0  |  提交时间：2013/03/25 Automatic target detection is very difficult in complicate background of sea and sky because of the clutter caused by waves and clouds nearby the sea-level line. In this paper  in view of the low-flying target near the sea is always above the sea-level line  we can first locate the sea-level line  and neglect the image data beneath the sea-level line. Thus the noise under the sea-level line can be suppressed  and the executive time of target segmentation is also much reduced. A new method is proposed  which first uses neighborhood averaging method to suppress background and enhance targets so as to increase SNR  and then uses the multi-point multi-layer vertical Sobel operator combined with linear least squares fitting to locate the sea-level line  lastly uses the centroid tracking algorithm to detect and track the target. In the experiment  high frame rate and high-resolution digital CCD camera and high performance DSP are applied. Experimental results show that this method can efficiently locate the sea-level line on various conditions of lower contrast  and eliminate the negative impact of the clutter caused by waves and clouds  and capture and track target real-timely and accurately.   Detection and tracking of low contrast targets based on integertype lifting wavelet transform (EI CONFERENCE) 会议论文 ICO20: Remote Sensing and Infrared Devices and Systems, August 21, 2005 - August 26, 2005, Changchun, China Wang L.; Shen X.; Wang Y. 收藏  |  浏览/下载：10/0  |  提交时间：2013/03/25 This paper presents a method for detecting and tracking of low contrast targets. The new method uses an integer-type lifting wavelet transform and the proposed method doesn't extract patterns similar to a template  but finds parts having the same feature in the targets. We utilize one of integer-type lifting wavelet transforms that contains rounding-off arithmetic for mapping integers to integers. The lifting term contains parameters that are learned by using standard training images of targets. We assume that the targets include many high frequency components. In order to obtain the features of the targets  the lifting parameters are determined by a condition that high frequency components are vanished in wavelet transform. But the condition cannot be determined by the parameters wholly. So  we put an additional condition of minimizing the squared sum of the lifting parameters. The advantage of using integer-type wavelet transform is simple and robust to noise. Simulation illustrated the approach can detect and track the moving targets in dim background. We would test our algorithm in the TV tracking system.