Solved by Alpha in post #2 
              
              
                I guess the last pooling layer in your implementation is AdaptivePool, which could deal with any size and the output is (b, c, 1, 1). So, it is ok to use 112x112. 
Besides, because the Mobilenetv2 has a downsample rate of 32 ,  your input size is OK when it is larger than 32. 
224x224 is a commonly …