I. Introduction
Image inpainting [1], [2], also known as image completion, aims to recover the masked areas for a damaged or missing image with plausible pixel values based on the information of the known areas. This task plays a significant role in the field of image processing and has been widely used in various applications [3]–[5] such as photo editing, object removal, and old photo restoration [6]–[8]. Thus, it has drawn continuous attention for decades [9]–[13].