An improved patch-based inpainting method for ancient mural images

Restoring the murals` various kinds of deterioration is urgently necessary, which gives the growing awareness of the need to protect cultural relics. Due to lack of original information to guide the whole inpainting process, patch-based methods, only using patch to search information from known parts of murals, were largely used in mural inpainting. Traditional patch-based method comprised by steps of patch selection and similarity computation, which often has the problem of searching mistakes such as discontinuous. To solve the problem of linear discontinuous happened through patch-based inpainting work, structure-guided patch selection and another way for similarity computation, considering more features of patches, were introduced in this paper. In the patch selection part, only major structure of image will be considered during patch priority computation. Through this step, the priority of patches in the edge of damaged part will be rethink and the overall computation time will reduce because of less unnecessary structure. In the similarity computation part, the local patch feature and global patch feature both will be considered rather than only considered local one in the traditional methods. Through this step, the patch feature will be comprehensively used in the inpainting work. This improved method was used in simulated murals and actual murals. It did better inpainting job than diffusion- based methods and other traditional patch-based methods, which not only improved linear continuous in some complex parts of mural but also reduced time-consuming.