“…In order to generate more photo-realistic results, Ledig et al further developed a GAN-based network, the SRGAN, which is a combination of SRResNet, the VGG-based perceptual loss, and a discriminator. Based on the success of SRResNet and SRGAN, many variants have been developed so far, including EDSR [20], RCAN [21], ASRResNet [8], IRL [22], and WDSRGAN [23]. EDSR eliminated the batch normalization layers and expanded the model size of SRResNet.…”