共查询到20条相似文献，搜索用时 15 毫秒
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针对场景照明变化、模型初始化以及阴影等问题, 提出了一种用于视频监视系统运动物体检测的统计多模态背景模型. 通过相隔固定的帧差值阈值化得到背景样本值, 并采用高斯核密度估计方法计算背景灰度的概率密度函数. 利用像素的邻域信息来去除由于摄像机抖动和场景小运动产生的噪声. HMMD色彩信息用来检测和抑制运动投射阴影. 实验结果验证了算法在交通监控前景物体分割中的有效性. 相似文献
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SHILi ZHANGZhao－yang 《上海大学学报(英文版)》2001,5(1):53-56
This paper presents a new approach to the extraction of a moving object from video sequence.The method is based on morphological motion filter using connected operator and a propsed new filtering criterion.The morphological motion filter aims to detect motion which is distinct from that of the background,and thereby locates independently moving physical objects in the secnes.Experiments show that the algorithm can extract object from moving backgrounds efficiently. 相似文献
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CHAI Deng-feng PENG Qun-sheng 《浙江大学学报(A卷英文版)》2007,8(8):1218-1226
This paper presents some techniques for synthesizing novel view for a virtual viewpoint from two given views captured at different viewpoints to achieve both high quality and high efficiency. The whole process consists of three passes. The first pass recovers depth map. We formulate it as pixel labelling and propose a bisection approach to solve it. It is accomplished in log2n（n is the number of depth levels） steps,each of which involves a single graph cut computation. The second pass detects occluded pixels and reasons about their depth. It fits a foreground depth curve and a background depth curve using depth of nearby foreground and background pixels,and then distinguishes foreground and background pixels by minimizing a global energy,which involves only one graph cut computation. The third pass finds for each pixel in the novel view the corresponding pixels in the input views and computes its color. The whole process involves only a small number of graph cut computations,therefore it is efficient. And,visual artifacts in the synthesized view can be removed successfully by correcting depth of the occluded pixels. Experimental results demonstrate that both high quality and high efficiency are achieved by the proposed techniques. 相似文献
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Traffic monitoring is of major importance for enforcing traffic management policies. To accomplish this task, the detection of vehicle can be achieved by exploiting image analysis techniques. In this paper, a solution is presented to obtain various traffic parameters through vehicular video detection system( VVDS). VVDS exploits the algorithm based on virtual loops to detect moving vehicle in real time. This algorithm uses the background differencing method, and vehicles can be detected through luminance difference of pixels between background image and current image. Furthermore a novel technology named as spatio-temporal image sequences analysis is applied to background differencing to improve detection accuracy. Then a hardware implementation of a digital signal processing (DSP) based board is described in detail and the board can simultaneously process fourchannel video from different cameras. The benefit of usage of DSP is that images of a roadway can be processed at frame rate due to DSP‘s high performance. In the end, VVDS is tested on realworld scenes and experiment results show that the system is both fast and robust to the surveillance of transportation. 相似文献
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Multi-face detection based on downsampling and modified subtractive clustering for color images 总被引：1，自引：0，他引：1
KONG Wan-zeng ZHU Shan-an 《浙江大学学报(A卷英文版)》2007,8(1):72-78
INTRODUCTION Face detection has been widely used in fields such as security, multimedia retrieval, human com-puter interaction, etc. Therefore it becomes one of the most active research areas in computer science. Re-cently, approaches to face detection include neural network (Rowley et al., 1998), boosting (Viola, 2001; Viola and Jones, 2004), template matching (Kim et al.,2000) and skin color (Cai and Goshtasby, 1999; Wang and Yuan, 2001; Soriano et al., 2003), etc. The methods of n… 相似文献
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1IntroductionBackground subtraction methods are extensively ex-ploited for moving object detection in videos in manyapplications ,such as traffic monitoring[1],human mo-tion capture[2]and video surveillance[3]. The centralidea behind such methods is to segment foreground ini mage sequences taken from a fixed camera by com-paring each newframe to a model of the scene back-ground . Therefore , correctly and efficiently modelingand updating the background model is one of the mostchallenging aspec… 相似文献
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为了提高人体运动位姿误差检测能力,提出基于双目视觉的运动位姿误差检测方法。采用双目视觉跟踪融合识别方法对运动位姿的样本动态特征点进行采样,以全局人体姿态信息为候选样本,进行运动位姿双目视觉特征高分辨提取,采用模板匹配方法,构建人体部位姿态候选样本轮廓分布集,获取模板大小,根据模板大小计算运动位姿的误差概率分布,利用相邻图像帧之间的运动特征分布集,构建运动位姿图像的位置信息检测模型,在此基础上,采用自适应颜色覆盖方法对运动位姿的误差概率分布做极小化处理,完成对人体运动位姿误差检测。仿真结果表明,采用该方法进行运动位姿误差检测的特征分辨能力很好,降低了检测误差,提高了运动位姿双目视觉跟踪识别能力。 相似文献
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针对跳水运动视频中的人体运动目标分割问题,提出一种简单有效的基于颜色特征运动目标检测及分割算法。首帧进行图像预处理,利用色相和亮度两个分量加强颜色差异,然后使用OTSU算法对图像进行阈值分割。结合RGB颜色空间启发式肤色聚类结果确定运动目标所在的连通区域,最终完成首帧运动目标的自动检测。有效地克服了复杂背景变化的影响,能够快速实现跳水运动目标的分割,且对运动对象的快速整体运动有较强的鲁棒性。 相似文献
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针对运动图像盲去模糊问题,基于生成对抗网络,提出利用一种端对端方式恢复模糊图像算法。运用生成对抗神经网络方法对运动模糊图像直接复原,跳过估计模糊核过程,增加感知损失作为损失项,使图片内容和全局结构接近。此外,增加结构相似性损失函数作为约束项,进一步提升生成图片与清晰图片的相似性。实验结果表明,新算法可有效去除运动图像模糊。与其它算法相比,所提算法获得的图像更加清晰。 相似文献
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本文采用了一种运动目标存在情况下的背景重建算法,能较好地抑制外界环境变化带来的影响。该运动目标检测算法通过一定数量帧的学习、统计,找到各坐标点像素灰度等级的分割阈值。在对当前帧图像进行背景差分后,分割出运动目标区域。若存在运动目标,则根据串行边界跟踪算法获得运动目标轮廓。获得边界后,模型将绘制方框显示运动物体,并发出警报。该运动目标检测模型用VisualC＋＋给予实现。 相似文献
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For the realtime classification of moving vehicles in the multi-lane traffic video sequences, a length-based method is proposed. To extract the moving regions of interest, the difference image between the updated background and current frame is obtained by using background subtraction, and then an edge-based shadow removal algorithm is implemented. Moreover, a thresholding segmentation method for the region detection of moving vehicle based on location search is developed. At the estimation stage, a registration line is set up in the detection area, then the vehicle length is estimated with the horizontal projection technique as soon as the vehicle leaves the registration line. Lastly, the vehicle is classified according to its length and the classification threshold. The proposed method is different from traditional methods that require complex camera calibrations. It calculates the pixel-based vehicle length by using uncalibrated traffic video sequences at lower computational cost. Furthermore, only one registration line is set up, which has high flexibility. Experimental results of three traffic video sequences show that the classification accuracies for the large and small vehicles are 97.1% and 96.7% respectively, which demonstrates the effectiveness of the proposed method. 相似文献
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文章介绍了彩色等离子显示器显示动态图像时的干扰及其形成机理,主要将AC-PDP和CRT发光的异同进行了比较和研究,指出了彩色AC-POP显示动态图像时干扰的出现是由子场驱动重显不同灰度造成的,彩色AC-PDP在显示运动物体时,由于人眼的视觉惰性就会出现不同时间发光的不均匀,从而在人眼视点跟随运动图像移动时,在视网膜上出现了虚假的轮廓干扰.文章最后介绍了显示动态图像时减少干扰的方法. 相似文献
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考虑到图像存在异常像素,将邻域因素考虑在内对模糊C-均值聚类算法(FCM)和异常像素检测算法(APD)提出了改进。首先,提出了邻域因素的邻域-FCM(N-FCM),然后,提出了模糊异常像素检测算法(Fuzzy-APD)。实验过程中,选择噪声图像、彩色图像作为实验图像,对FCM和N-FCM算法进行性能比较,证实相比于FCM算法,N-FCM算法的收敛性明显提高,图像分割的正确率进一步改善;同时从图像中获取部分像素进行异常像素检测,实验证实相比于异常像素检测,Fuzzy-APD准确性更高。 相似文献
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提出一种既能快速去除图像随机脉冲噪声又能较好地保留边缘细节信息的一种新方法。该方法首先利用图像局部灰度相似性特征,对于任一像素,根据其与邻域内像素相近的个数和与其相近像素本身在邻域内的相似情况,将各像素分为噪声点、疑似噪声点和信号点,对疑似噪声点根据其是否为邻域内的极值将其分为噪声点和信号点。对于信号点不做任何处理,而对于噪声点则按照一种基于欧拉距离的自适应加权均值滤波算法进行处理。实验结果表明,算法能够快速高效地滤除随机脉冲噪声,且无需人为修改相关参数和“门坎”值,综合性能优良,特别适用于对实时性要求较高的图像处理系统。 相似文献
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杨仙维 《武汉职业技术学院学报》2013,12(3):80-85
提出一个基于区块差值分布之彩色BMP图文件可回复信息隐藏法,先将彩色BMP图档的像素切割成不重迭长宽各3个像素的区块,每个区块中用特定方式选择其中一个像素,计算其他8个像素和此像素的RGB颜色绝对差值,利用这些差值来产生分布图,在分布图中找出适合的峰点和零点,将峰点和零点内的区域向右位移1个颜色差值,就能将位形式的信息藏入峰点颜色差值的像素中,藏入信息的图文件仍能保持良好质量,肉眼无法察觉差异,经实验证明本研究提出的方法可隐藏大量信息并维持良好的图片质量。 相似文献
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The onset of motion was used to study stimulus-driven visual attention in 14-week-olds. The movement of an object did not capture attention reflexively at 14 weeks of age. The attention-getting properties of a moving stimulus depended significantly on its color in combination with the colors of other objects in the visual field. Specifically, detection of a green moving target was masked in the presence of mixed red and green static objects. No such masking was observed when the moving target was red or when the green target moved in a visual field that was populated only with green objects. The same effect was observed to a lesser extent when the green bars were replaced with gray bars. The number of distractors in the visual field exerted an effect on the accuracy of detection only when their appearance in the visual field was coincident with the onset of target motion. Attention to motion at this age is not independent of the structure of the visual field; chromatic preferences play a role in how readily infants attend to a moving object. These effects may be mediated by a difficulty in disengaging attention (from distractors) or in suppressing attention to competing objects once attention is engaged on a target. 相似文献