Solved by andreaskoepf in post #2 
              
              
                To rescale a 2D 1-channel image the input should be 4D: batch x chan x height x width 
The error message indeed is a bit unclear. 
See the interpolate() in the docs: 
"Currently temporal, spatial and volumetric sampling are supported, i.e. expected inputs are 3-D, 4-D or 5-D in shape. 
The input dim…