About norm_scale function for JHMDB

[HappyDeepLearning]

I find this line https://github.com/fandulu/DD-Net/blob/f26a9994b0bafc41096fa269eab89c2757d71499/JHMDB/utils.py#L38 is (x - np.mean(x)) / np.mean(x) to norm the data. I'm confuse for this line. Could you give me some advises?

I think it should be (x - np.mean(x)) / np.std(x)