A computer-implemented method is provided. The computer-implemented method includes inputting a low-resolution image into a generator; and generating a high-resolution image using the generator based on the low-resolution image. Generating the high-resolution image includes processing the low-resolution image through a plurality of super-resolution generating units arranged in series in the generator. A respective output from a respective one of the plurality of super-resolution generating units has a respective increased image resolution as compared to a respective input to the respective one of the plurality of super-resolution generating units.