VALID:
output_height = (in_height - filter_height)/strides_height + 1
output_width = (in_width - filter_width)/strides_width + 1
SAME:
output_height = in_height/strides_height
output_width = in_width/strides_width
综合:
out = (in - filter_size + 2*padding)/strides + 1