Question about visualizing the gradient

[George1ee]

Thanks for your code and I lean a lot from it. However, when I read your code, I do get a question:

In the paper, you stated "we visualize the gradients of the loss with respect to individual features
(pixels)" . But the gradient of a pixel should have 3 dimensions (since it is RGB), so how you visualize it? (get the average or max or ...?)