Denoise the same picture with different nets

[sdlpkxd]

Hi, Thanks for your codes at the first. I am confused by a phenomenon. I have trained 3 nets with sigma = 5,10,15 respectively and I get a noised picture with sigma = 5. Then I used three trained nets to denoised the same picture, but I find the net trained with sigma = 5 performs worse than other two nets. And I find the nets with sigma = 15 performs best. I am confused by this phenomenon, do you know the reason?

[mmmusong]

sigma is parameters based on human, not based net. it's a kind of hyperparameters