基于视觉曲率估算的文物线图绘制方法

针对表面富含噪声的文物三维模型特征线的有效提取问题,分析了预处理阶段导致纹理细节丢失的原因,提出了一种基于视觉曲率估算的文物线图自动绘制方法。首先,对三角网格模型顶点的高度函数空间进行均匀采样,通过统计高度函数中极值点的个数,实现对模型顶点的视觉曲率估算；然后,根据多尺度约束下模型顶点的视觉曲率分布,将模型划分为平坦区域和特征区域；接着,依据考古领域均值对特征区域的顶点进行锐化滤波,计算出新的三角网格模型的顶点坐标；最后,对三角网格模型提取特征轮廓线,实现对文物线图的自动绘制。实验结果表明,基于视觉曲率的特征轮廓线在保留文物模型表面纹理细节的同时,有效避免了简单脊线/谷线法绘制线图呈现的尖锐现象。

Drawing Method of Cultural Relics Line Drawing Based on Visual Curvature Estimation

In order to solve the problem of the effective extraction of the feature lines of the three-dimensional model whose surface has noise,the reasons for the loss of texture details in the preprocessing stage was discussed and a new method of line drawing based on visual curvature estimation of the cultural relics was proposed.First, the discrete curvature on triangular mesh vertex is estimated and the cultural relic model is divided into the flat region and the non-flat region according to the curvature distribution.Then the sharpening filter on the vertex of the non-flat region is conducted to calculate the new mesh vertex coordinates.Finally,based on the visual curvature,the curved contour line is extracted to achieve automatic drawing of line drawing of cultural relics of the triangular mesh model.The experimental results show that the non-flat contour lines based on the visual curvature remains the details of the surface texture of the 3D model and avoid the sharp phenomena of the line drawing of the directed ridge line & valley line drawing.