要求做一个实验，对一副M*N大小的图像重复使用截频为D0的高斯低通滤波器进行滤波。假设K为滤波次数。当K足够大时，滤波结果是什么样？并从理论上说明这一结果产生的原因。

-Asked to do an experiment on a M* N image size cutoff frequency reuse as D0 Gaussian low-pass filter for filtering. Assuming K is the filter frequency. When K is large enough, the result is what kind of filter? Theoretically explain the reasons for this result produced.