The accurate alignment of 3D woodblock geometrical models with 2D orthographic projection images presents a significant challenge in the digital preservation of Vietnamese cultural heritage. This paper proposes a unified image processing algorithm to address this issue, enhancing the registration quality between 3D woodblock models and their 2D representations. The method includes determining the plane of the 3D character model, establishing a transformation matrix to align this plane with the 2D printed image plane, and creating a parallel-projected depth map for precise alignment. This process minimizes disocclusions and ensures that character shapes and strokes are correctly positioned. Experimental results highlight the importance of structure-based comparisons to optimize alignment for large-scale Han-Nom character datasets. The proposed approach, combining density-based and structure-based methods, demonstrates improved registration performance, offering an effective normalization scheme for digital heritage preservation.

翻译：三维木刻几何模型与二维正投影图像的精确配准，是越南文化遗产数字化保存中的一项重大挑战。本文提出一种统一的图像处理算法来解决此问题，以提升三维木刻模型与其二维表示之间的配准质量。该方法包括确定三维字符模型的平面、建立变换矩阵以将该平面与二维印刷图像平面对齐，以及创建平行投影深度图以实现精确配准。此过程最大限度地减少了遮挡缺失，并确保字符形状和笔画正确定位。实验结果凸显了基于结构的比较对于优化大规模汉喃字符数据集配准的重要性。所提出的方法结合了基于密度和基于结构的方法，展示了改进的配准性能，为数字遗产保存提供了一种有效的归一化方案。