Super-resolution using multi-channel merged convolutional network

Single-image super-resolution (SISR) has been an important topic due to the demand for high-quality virtual images in the field of visual artificial intelligence. Methods based on deep learning have achieved great success based on the excellent capability of grasping complicated features of deep convolutional networks. The performance can be improved slightly but not obviously by simply widening or deepening the network. In this paper, we propose a merged convolutional network for super-resolution, which extracts more adequate details to restore high-resolution images. We used dense blocks for feature extraction to concatenate deep features with shallow features in depth. We also designed two sub-nets with distinct convolution kernels as different branches of the network, which can widen the network and improve the performance of the system. Finally, we employed sub-pixel layers to avoid feature distortion for up-sampling at the very end. Our method was evaluated using several standard benchmark datasets. The results demonstrate superior performance and good robustness compared with state-of-the-art methods. (C) 2019 Elsevier B.V. All rights reserved.