serious artifacts with the results

[Ethean]

I generate the blur kernel with matlab code

mu=[0,0];
[X,Y]=meshgrid(-10:1:10,-10:1:10);
j = 9;
out_path = 'kernels21/G/';
if isdir(out_path)==0
mkdir(out_path)
end
for i = 0:0
for k = 2.5:0.5:6
sigma = [k i ; i k];
kernal = mvnpdf([X(:) Y(:)],mu,sigma);
k = reshape(kernal, size(X));
save([out_path, int2str(j), '.mat'], 'k')
j = j+1;
end
end

and blur the image with opencv function filter2D and input the generated image and kernel lable to test. But I get results with serious artifacts, examples are as follows


I don't know why it happens.

[cszn]

from scipy import ndimage
img_blurry = ndimage.filters.convolve(img_H, np.expand_dims(kernel, axis=2), mode='wrap')

[Ethean]

Thanks you for replying me. I am still confused that the kernel in code is the real kernel used to super resolve the blur image? If not, how can I get the kernel? Thanks in advance!

[Ethean]

Oh, I get you. You mean I should generate the lr image in this way, then test the model on the synthesised images.