提出了一种新的ＭＰＥＧ－２ＶＢＲ视频场景切换判别法．此判别法表明，相邻编码帧宏块条码率的频域互相关能够有效反映图像活动性变化的特点．以此作为判决准则，将频域互相关的结果与自适应门限进行比较，可以准确地判断出运动图像场景发生切换的位置及其帧类型，具有实现简单，计算量少的优点，可以满足实时应用． A new MPEG-2VBR video scene switching discriminant method is proposed. The discriminant method shows that the cross-correlation of the bar code rate of adjacent coded frames can effectively reflect the characteristics of the change of the image activity. Using this as a decision criterion, comparing the result of cross-correlation in frequency domain with the adaptive threshold can accurately determine the position and the frame type of the switching of the scene of the moving image, which has the advantages of simple implementation and less calculation, and can satisfy real-time application.