Why need to switch dim2 a dim3 when convert Caffe weights to PyTorch?

[mayuanjason]

Hi TropComplique,

First, very appreciate for your great work, learned much from your source code.

I have one question, why we need to switch dim2 a dim3 when convert Caffe weights to PyTorch like below:

extract_weights_from_caffe_models.py
all_weights[name + '.weight'] = net.params[p][0].data.transpose((0, 1, 3, 2))

Does the shape of Caffe weight is [N, C, W, H]? So we need to change it to [N, C, H, W], right?

Hope for your reply.