1. A method for upsampling an image, comprising: upsampling the image using a non-linear fully connected network to produce only global details of an upsampled image; interpolating the image to produce a smooth upsampled image; concatenating the global details and the smooth upsampled image into a tensor; and applying a sequence of nonlinear convolutions to the tensor using a convolutional neural network to produce the upsampled image, wherein steps of the method are performed by a processor.