中文说明：The reason that the way of calculating the total variance is a good qualitative method of describing how the image is affected with the added noise, is that the output of the total variance formula is describing how the value of the pixels of the image were close to each other. This was done through summation of the average variance in a window of 3X3 pixels. The calculation begins with getting the average value of the pixels in the 3X3 window. Then seeing how the pixels values in the window are close to the average value by subtracting each pixel in the window by
English Description：
The reason that the way of calculating the total variance is a good