Challenges in Image Matching for Cultural Heritage: An Overview and Perspective

Image matching, as the task of finding correspondences in images, is the upstream component of vision and photogrammetric applications aiming at the reconstruction of 3D scenes, their understanding and comparison. Such applications are of special importance in the context of cultural heritage, as they can support archaeologists to digitally preserve, restore and analyze antiquities, but also to compare their changes over time. The success of deep learning, now firmly established, paired with the evolution of computer hardware, has led to many advances in image processing, including image matching. Despite this progress, image matching still offers challenges, in terms of the matching process itself but also on other practical and technical aspects. This paper gives an overview of the current status of the research in image matching with a particular focus on cultural heritage, presenting both strengths and weaknesses of the most recent approaches by means of visual comparisons on exemplar challenging image pairs. Besides assisting researchers and practitioners in the choice of the most suitable solution for a given task, this analysis also suggests lines of research worth to be investigated by the community in the near future.