vutils. make_ A little experience of grid () in relation to black and white images

I found that vutils.make_grid() Inside the black-and-white image of the flyer channel , It will eventually become a three channel image

The intercepted code is like this , among fake The shape is 64 * 1 * 64 * 64, yes 64 Black and white image data , And when debugging, it goes img_list After adding an element , The element shape is 3 * 64 * 64