提出一种基于像素块最大后验概率的视频运动对象快速分割算法。首先根据连续3帧视频序列构建参考帧，计算基于像素块的差分图像；然后用Gibbs随机场模型描述基于像素块的差分图像，通过最大后验概率方法分割运动对象块；最后使用基于颜色梯度的snake模型提取运动对象轮廓。实验结果表明，该算法能避免视频对象的缺失，降低图像噪声的影响，减少误分割，同时具有较快的计算速度。

A video object segmentation method based on MAP (maximum a posteriori) of pixel blocks is proposed. Firstly, a reference frame is built from three continuous frames and a pixel block-based difference image is calculated. Secondly, a pixel block-based difference image is described by Gibbs random field model, the moving object blocks are detected by MAP. Last, the contour of the moving object is extracted by the snake method. The experiments results show that the algorithm can avoid the losing and mistakes with a good speed.