A Fast And Efficient Super-Resolution Network Using Hierarchical Dense Residual Learning

In deep convolutional neural networks (DCNNs) for single image super-resolution (SISR), the dense and residual feature refinement helps to stabilize the training network and enriches the feature values. However, most SISR networks do not fully exploit the rich feature information in the hierarchical dense residual connections, thus achieving relatively low performance. Besides, in many cases, a large model is not feasible to deploy on mobile or embedded devices. By exploiting the hierarchical dense residual learning, this paper proposes a fast and efficient hierarchical dense residual network (HDRN) to solve these problems. Specifically, we develop a dense compact residual group (DCRG), consisting of several compact residual blocks (CRB), by using multi-level residual and dense skip connections. Our experimental results confirm that the proposed HDRN achieves a better trade-off between the performance and computational costs than those state-of-the-art lightweight SISR methods.