Swaps the values of incoming grids while preserving the number of Dimensions between incoming and outgoing grids. dimension number of the dimension by which the reverse will occur. For N-dimensional grids, the dimensions are numbered from 0 to N-1. In addition, negative numbers from -N to -1 may be used, to which N will be added. grid to be reversed reversed grid for an image, 0 or -3 does vertical flip, 1 or -2 does horizontal flip, and 2 or -1 does channel flip. if you do this on something else than an image, you may see why the negative numbers are supported: if you make a grid of multiple images, then -1 will always refer to the channels dimension no matter what.