Developing an Objective Visual Quality Evaluation Pipeline for 3D Woodblock Character

Vietnamese feudal dynasty woodblocks are invaluable national treasures, but many have been lost or damaged due to wars and poor conditions of preservative environments. Fortunately, 2D-printed papers of the damaged or lost woodblocks have been well-preserved, allowing for reconstruction their 3D digital version. To ensure accurate reconstruction of 3D woodblocks, it is essential to have a reliable alignment method that closely matches human visual perception. In this paper, we introduce an automatic pipeline for objective visual quality evaluation of woodblock characters. The pipeline includes two components: the first shifts the quality evaluation from 3D domain to 2D domain by employing orthogonal projection to transform a 3D mesh woodblock character model into a 2D depth map image with minimum information loss. The second utilizes established 2D perceptual metrics, which closely align with human visual perception, to evaluate the 2D depth map. Our evaluation demonstrates that features of these proposed perceptual metrics employed in the pipeline can effectively characterize the visual appearance of the woodblock character based on our prepared dataset. Additionally, the experiments presented in the paper also demonstrate that these metrics can sensitively detect degradation levels in both the foreground and background components of a woodblock character.