FAN: Frequency Aggregation Network for Real Image Super-resolution
It addresses the problem of restoring high-resolution images from low-resolution inputs with authentic degradations for applications in image processing, but it is incremental as it builds on existing deep learning methods.
The paper tackles real-world single image super-resolution with complex degradations by proposing FAN, a frequency aggregation network, achieving fourth place in the AIM 2020 challenge with a PSNR of 31.1735 and SSIM of 0.8728 on the X4 track.
Single image super-resolution (SISR) aims to recover the high-resolution (HR) image from its low-resolution (LR) input image. With the development of deep learning, SISR has achieved great progress. However, It is still a challenge to restore the real-world LR image with complicated authentic degradations. Therefore, we propose FAN, a frequency aggregation network, to address the real-world image super-resolu-tion problem. Specifically, we extract different frequencies of the LR image and pass them to a channel attention-grouped residual dense network (CA-GRDB) individually to output corresponding feature maps. And then aggregating these residual dense feature maps adaptively to recover the HR image with enhanced details and textures. We conduct extensive experiments quantitatively and qualitatively to verify that our FAN performs well on the real image super-resolution task of AIM 2020 challenge. According to the released final results, our team SR-IM achieves the fourth place on the X4 track with PSNR of 31.1735 and SSIM of 0.8728.