为了对视频序列中的运动目标进行快速、准确地提取,提出了一种自适应背景模型估计方法。利用背景与前景图像在时域中不同的变化特性,构造图像的稳定矩阵函数,通过稳定矩阵元素的变化自动区分背景点和前景点,并对稳定矩阵设置上、下饱和值,使算法能在短时间内自动感知背景的突变,从而快速地建立背景图像模型并对其实时更新。同时还分析了动态图像序列的配准问题,选取局部特征模板图像,采用投影匹配原理简化计算,快速估计出全局运动矢量。实验证明,背景估计算法收敛速度快,只需10 frame图像即可建立稳定背景,对于500 pixel×200 pixel动态图像序列,整个算法时间只需35 ms,完全满足工程上25 frame/s处理能力的要求。

To extract the moving target in video sequence fast and exactly,a self-adaptive background estimation technique was developed.Because of the different time-variability between background and foreground,a stability matrix was constructed,and according to its changes the background points could be distinguished from the foreground points.By setting two saturation values to the stability matrix,the algorithm could perceive the saltation of background automatically and update the background image quickly.Besides,in order to register the dynamic image sequences some local features were selected as templates,and projection matching technique was used to simplify the calculation and quicken the offset estimation.The experiment results show this algorithm has a high rate of convergence that only 10 frame are needed to get a stable background image,and the whole time is only 35 ms.So it meet the need of a processing ability of 25 frame/s in engineering.