分析了微分滤波对联合变换功率谱的影响，得到了一种称之为功率谱形式的微分滤波器。该滤波器的滤波函数为一实数并且有一定的特点，因此很容易制得。计算机模拟表明，功率谱微分滤波联合变换相关器在相关峰值、旁瓣比、半宽度等方面比一般联合变换相关器有显著的改善，可以大大提高相关图像识别的可靠性。文中给出了实验结果，与模拟计算结果吻合，引入一个新参数可以更好地描述相关图像识别中的相关性。

In this paper, the effect of differential filter on joint power spectrum has been analyzed and so-called power spectrum differential filter is introduced. The function of this filter is real with some peculiarity, so it is easy to make. Computer simulations indicate that the performance of power spectrum differential filter joint transform correlator (JTC) is improved obviously than that of a classical JTC in the areas of peak intensity, Peak-to-sidelobe, half correlation width and so on. It will greatly enhance the reliability of pattern recognition. The experimental result is agreement with that of computer simulation. A new parameter is introduced in this paper that can discribe correlation better.