HELP trying VDSR example

Hi,

I am trying VDSR example available here https://www.mathworks.com/help/images/single-image-super-resolution-using-deep-learning.html#VeryDeepSuperResolutionDeepLearningExample-9

can this example work with grayscale image ?? and is there any possibility to do it with a personal laptop (intel i5), because we are trying that and it takes a lot of time and we doubt that the results are correct (the graph of training process isn't good and progressing )??

Thanks