针对传统运动目标检测方法在背景和目标都存在运动时，无法进行有效的运动目标检测的问题，提出了一种动态背景下红外运动目标检测算法。首先，提出了一种基于帧差法的图像匹配特征块选取方法，并结合改进的互信息测度对相邻图像进行背景匹配；接着对匹配后的图像进行帧差处理，给出了基于特征块的阈值确定方法；并对分割后的图像进行形态学滤波去除孤立干扰点；最后，利用图像投影的方法得到运动目标区域，完成运动目标的检测。仿真实验表明，该算法能减少背景干扰，突出运动目标，有效地检测出变化背景中的运动目标。Detection on Dynamic Background

The traditional moving object detection algorithms cannot work when both background and objects are in moving state. A method of infrared image moving object detection is proposed on moving background. First a selecting method of image characteristic block based on frame differences is proposed and the improved mutual information measure is combined to match background. Then the matched images are dealt with frame differences and the frame differences image is segmented by the threshold which is gotten based on image characteristic block. The background noise is wiped off by using morphology method. At last, the object detection is completed by image projection. Experiments show that the proposed algorithm can eliminate background motion effectively and detect the moving objects on the moving background accurately.