共查询到16条相似文献,搜索用时 218 毫秒
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智能交通系统运动车辆的光流法检测 总被引:1,自引:0,他引:1
基于视频的车辆检测在智能交通系统中有着重要的实用价值.提出了一种在复杂背景中检测运动车辆的方法,针对传统光流法在阴影、边界和遮挡的地方灰度守恒和光流场平滑性假设不再成立这一问题,引入前向-后向光流方程,计算其Hessian矩阵,并把Hessian矩阵的条件数与Lucas-Kanade光流法中的加权阵相结合,有效地消除了局部邻域中不可靠的约束点,同时进一步提高了光流约束方程解的稳定性.实验结果表明:该方法检测情况稳定,检测准确率高,检测效果好.检测结果可作为智能交通系统中高层交通管理和车辆控制的基础. 相似文献
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提出了一种基于MRF的复杂背景下缓目标分割方法.该方法采用基于逆向光流场的背景抑制技术和基于加权直方图的灰度场建模方法.前者对相邻视频图像进行逆向光流变换使得两帧图像中的目标投影对齐,进而对两帧图像进行差分运算并设定阈值分离目标和背景,得到了较为完整的缓动目标初始分割;后者对初始标号场各像素分配信任度,进而统计信任度并建立加权灰度直方图,而后依据加权直方图建立了准确的图像灰度模型.在此基础上,在MAP-MRF框架内对视频图像进行分割.进行仿真实验并采用空间准确度和时间一致性标准评价实验结果,证明算法具有有效性和鲁棒性. 相似文献
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为了避免传统基于RGB颜色模型方法在方程组中各等式线性相关和存在孔径的问题,提出一种在HSI颜色模型下结合小波变换的方法计算彩色图像视频序列光流场的计算方法,这里将传统的灰度图像光流估计方法与HSI颜色模型估计方法相结合,并且用小波变换方法对光流矢量场的异常数据点或因为匹配错误而产生的异常块数据进行剔除,从而有效提高光流场估计精度,得到精密的彩色图像光流矢量场特征。 相似文献
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基于边缘定向扩散方程的图像复原方法 总被引:6,自引:2,他引:4
讨论了光学图像中同时存在噪声与模糊时的复原问题。采用一种能根据边缘方向自适应选取扩散系数的各向异性扩散方程来约束复原后的图像的光滑性质,将其和图像复原模型一起使用,得到了一种图像复原的正则化模型,并利用Eluer方程将该模型转换成一种可以快速求解的各向异性非线性扩散模型。在光滑性约束项的构造上,构造了一种基于边缘定向扩散的各向异性张量型扩散方程,能有效地根据边缘的方向确定是增强边缘还是滤除噪声。相比图像复原的迭代正则化方法,新方法能在复原图像的同时有效地抑制噪声,并有效地减轻边缘处的振铃效应。数值计算结果表明,新方法在整幅图像的复原效果上明显强于迭代正则化方法,尤其在对背景噪声的抑制上效果更明显,峰值信噪比(PSNR)也比迭代正则化方法平均提高了约2dB。 相似文献
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讨论了光学图像中同时存在噪声与模糊时的多幅图像问题.利用一种能根据边缘方向自适应选取扩散系数的各向异性扩散方程,对图像进行复原.在权函数取值上,根据影响图像复原的降质矩阵和噪声2个因素,构造了合理的权函数.考虑了成像的归一化方程,以减小不同噪声水平的影响;采用仿真方法对不同降质矩阵在相同干扰下的扰动进行估计,获得了降质矩阵的病态程度对复原效果的影响.与传统方法相比,该方法能够选择性地根据噪声和降质获得权值,正确地衡量不同图像对复原问题的贡献,改进处理结果.数值计算结果表明,新方法能获得较传统方法更好的复原图像,权值的选择与单幅图像复原的结果一致. 相似文献
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Jun Liu Zhongdan Huan Haiyang Huang 《Journal of Visual Communication and Image Representation》2011,22(3):263-270
The total variation based regularization method has been proven to be quite efficient for image restoration. However, the noise in the image is assumed to be Gaussian in the overwhelming majority of researches. In this paper, an extended ROF model is presented to restore image with non-Gaussian noise, in which the locations of the blurred pixels with high level noise are detected by a function and two estimated parameters of noise, while the fidelity and smoothness terms can be adaptively adjusted by updating these parameters. In contrast to the previous method, our model can give a much better restoration in some particular cases, such as the blurred image corrupted by impulsive noise and mixed noise. Moreover, the proposed minimization problem is solved by the split Bregman iteration, which makes our algorithm very fast. We provide some experiments and comparisons with other methods to illustrate the high efficiency of our method. 相似文献
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In the computation of dense optical flow fields, spatial coherence constraints are commonly used to regularize otherwise ill-posed problem formulations, providing spatial integration of data. We present a temporal, multiframe extension of the dense optical flow estimation formulation proposed by Horn and Schunck (1981) in which we use a temporal coherence constraint to yield the optimal fusing of data from multiple frames of measurements. Conceptually, standard Kalman filtering algorithms are applicable to the resulting multiframe optical flow estimation problem, providing a solution that is sequential and recursive in time. Experiments are presented to demonstrate that the resulting multiframe estimates are more robust to noise than those provided by the original, single-frame formulation. In addition, we demonstrate cases where the aperture problem of motion vision cannot be resolved satisfactorily without the temporal integration of data enabled by the proposed formulation. Practically, the large matrix dimensions involved in the problem prohibit exact implementation of the optimal Kalman filter. To overcome this limitation, we present a computationally efficient, yet near-optimal approximation of the exact filtering algorithm. This approximation has a precise interpretation as the sequential estimation of a reduced-order spatial model for the optical flow estimation error process at each time step and arises from an estimation-theoretic treatment of the filtering problem. Experiments also demonstrate the efficacy of this near-optimal filter. 相似文献