AM-ESRGAN: Super-Resolution Reconstruction of Ancient Murals Based on Attention Mechanism and Multi-Level Residual Network

To address the issues of blurred edges and contours, insufficient extraction of low-frequency information, and unclear texture details in ancient murals, which lead to decreased ornamental value and limited research significance of the murals, this paper proposes a novel ancient mural super-resolution reconstruction method, based on an attention mechanism and a multi-level residual network, termed AM-ESRGAN. This network builds a module for Multi-Scale Dense Feature Fusion (MDFF) to adaptively fuse features at different levels for more complete structural information regarding the image. The deep feature extraction module is improved with a new Sim-RRDB module, which expands capacity without increasing complexity. Additionally, a Simple Parameter-Free Attention Module for Convolutional Neural Networks (SimAM) is introduced to address the issue of insufficient feature extraction in the nonlinear mapping process of image super-resolution reconstruction. A new feature refinement module (DEABlock) is added to extract image feature information without changing the resolution, thereby avoiding excessive loss of image information and ensuring richer generated details. The experimental results indicate that the proposed method improves PSNR/dB by 3.4738 dB, SSIM by 0.2060, MSE by 123.8436, and NIQE by 0.1651 at a $\times 4$ scale factor. At a $\times 2$ scale factor, PSNR/dB improves by 4.0280 dB, SSIM increases by 3.38%, MSE decreases by 62.2746, and NIQE reduces by 0.1242. Compared to mainstream models, the objective evaluation metrics of the reconstructed images achieve the best results, and the reconstructed ancient mural images exhibit more detailed textures and clearer edges.