An Image Decomposition-Guided Network for Image Interpolation

A novel image decomposition-guided network (IDGN) for image interpolation is proposed in this paper by incorporating the fundamentals of subband image decomposition into the design of our deep-learning network. In our work, a filter bank consisting of a Gaussian filter and a differenceof-Gaussian filter is designed for decomposing the low-resolution input image into multiple subbands of the same resolution without downsampling. These subbands are inherited with different low-frequency and high-frequency information and are ready to be interpolated individually in our developed network. For training our IDGN, the decomposed low-resolution subbands need to be paired up with their corresponding ground-truth high-resolution subbands. Since our human visual system is sensitive to high-frequency signals, a perception-regulated (PR) loss function is proposed to guide our IDGN by putting more emphasis on the high-frequency subbands during the training process. Extensive experimental results have shown that our IDGN can achieve superior performance when compared with a number of state-of-the-art image interpolation methods.