Taking MSE loss as an example, what should be measured is the difference between the pixel value at a certain coordinate in the moving image and the pixel value after adding d(x) to the coordinate in the fixed image, that is, change it to IM(x)- IF(x+d(x)).
Taking MSE loss as an example, what should be measured is the difference between the pixel value at a certain coordinate in the moving image and the pixel value after adding d(x) to the coordinate in the fixed image, that is, change it to IM(x)- IF(x+d(x)).