The other way would be to skip the upsampling and just pass your input as it is to the model.
Since the size of your input is large enough, you would just have to change the in_features of the Linear layer.



 ptrblck:

Alternatively, your input is not too small for the used layers of resnet, so you could still pass it as [3, 256, 128] and set in_features in augmentedX to (ni * 8 * 4) , where ni=2048 .