图像缺损修复研究旨在通过计算机自动修复图像中的缺损内容。近年来，深度神经网络技术的出现有效 促进了相关研究的发展。本文针对该类研究进行了系统梳理和综合介绍。依据网络架构类型，具体将方法分为五 类：Context-Encoder 类、U-Net 类、CGAN 类、DCGAN 类以及 StackGAN 类。我们具体分析了每类方法的思路、 特点、优势和缺陷，并基于系统性实验，在公开大规模数据集上客观对比评价每一类方法的精度和性能。最后对 目前相关工作中存在的问题和挑战进行了阐述和介绍。
The image nonlocal self-similarity (NSS) prior refers to the fact that a local patch often has many nonlocal similar patches to it across the image and has been widely applied in many recently proposed machining learning algorithms for image processing. However, there is no theoretical analysis on its working principle in the literature. In this paper, we discover a potential causality between NSS and low-rank property of color images, which is also available to grey images. A new patch group based NSS prior learning scheme is proposed to learn explicit NSS models of natural color images. The numerical low-rank property of patched matrices is also rigorously proved. The NSS-based QMC algorithm computes an optimal low-rank approximation to the high-rank color image, resulting in high PSNR and SSIM measures and particularly the better visual quality. A new tensor NSS-based QMC method is also presented to solve the color video inpainting problem based on quaternion tensor representation. The numerical experiments on large-scale color images and videos indicate the advantages of NSS-based QMC over the state-of-the-art methods.