[deep learning] storage form of nchw, nhwc and chwn format data

    The data in deep learning is generally 4D Of ,NCHW or NHWC Format . among ：N representative  Batch,C representative Channel,H representative Height,W representative Width.

    Although the logical expression is 4 Dimension data , But when it is stored in the computer, it is in accordance with 1D To store the . Physical storage ：

    NCHW First take W Direction data ; And then there was H Direction ; And then C Direction ; Finally, take N Direction data .NHWC and CHWN Format and so on .