1. Introduction
Image Super-Resolution refers to those set of techniques that increase the resolution of an image while maintaining its quality that is commonly measured in terms of Peak Signal to Noise Ratio (PSNR [29]), and Structural Similarity (SSIM [97]) w.r.t. the ground-truth. Recent advances in display device technologies (Full HD and higher resolutions) have brought a surge in the application of super-resolution thus making it a prominent Computer Vision problem that is gaining immense academic and commercial research interests.