基于法向域的浅浮雕风格化设计

摘要

This paper presents an approach of bas-relief stylization based on normal field. To this end, our method reconstructs the resulting bas-relief with the altered local details by solving a global optimization. First, Gaussian filters are used to extract the high-frequency information and low-frequency information from an initial height image. Next, the separate height images are respectively transformed into two normal images by a bilateral surface fitting method. The separate normals are edited respectively using different stereographic mapping methods. Finally, a bas-relief is generated by solving a sparse linear system in the least-squares sense. By extracting different frequencies from a height field and editing them on normal do-main, our approach naturally preserves and enhances the fine details of model and produces bas-reliefs with different styles. The experimental results show that our approach is easy to implement, and effectively demonstrate its ability to restyle digital bas-reliefs.%针对数字浅浮雕设计，通过对已有浅浮雕进行整体优化以及局部细节特征的调整来获得不同风格样式的浅浮雕，提出了一种基于法向域的浅浮雕重新风格化方法。首先使用高斯滤波提取初始浅浮雕高度图的高频信息和低频信息，分别表示浅浮雕的细节特征和整体形状；然后通过双边曲面拟合将高频和低频高度图转化为法向图，获得不同频域的法向信息；再运用不同投影方式的球极映射对这2个频域的法向进行编辑；最后通过最小二乘法重建出新的高度图，获得风格迥异的浅浮雕模型。该方法通过分离浅浮雕模型上不同频率的特征信息并在法向域上分别处理，不仅自然地保留和增强了模型表面的特征细节，而且得到了各种异于原浅浮雕模型的风格效果。实验结果表明，文中方法简单有效，为浅浮雕的设计制作提供了新的思路和方法。