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| 结合纹理特征的多边形模型简化算法研究 | |
| Alternative Title | Study on Polygonal Simplification Algorithms with Texture Features |
| 郭力真 | |
| Major | 计算机应用技术 |
| 2004 | |
| Degree Grantor | 中国科学院软件研究所 |
| Degree Level | 博士 |
| Place of Degree Grantor | 中国科学院软件研究所 |
| Keyword | 多边形模型简化 误差度量 纹理 扭曲 |
| English Abstract | 多边形模型是图形学中最重要的模型表示形式。它的简化和多分辨率表示有重要的应用价值。本文针对这一类模型的简化进行了如下研究工作：第二章就多边形模型简化算法，给出一个综述。首先介绍误差度量准则，然后对简化算法根据基本简化机制进行分类介绍。最后介绍了在简化模型中保持属性特征的一些典型方法。当前的很多模型常常带有纹理图像，以便在绘制时增加细节，提高真实感。第三章提出一种结合纹理特征的模型简化算法。该算法考虑了纹理扭曲的成因和纹理图像内容对视觉的影响，用边缘检测的方法度量纹理图像上不同区域对视觉影响的大小，用纹理密度（三角形对应纹理区域的大小和它在三维空间中面积的比值）的变化度量纹理扭曲发生的可能性和严重程度，并把这些与纹理相关的误差度量和几何误差度量结合。该算法生成的简化模型保持了较好的视觉特征。第四章提出一种防止纹理扭曲的模型简化算法。从另一个角度对一纹理扭曲的产生原因进行了分析，认为纹理扭曲主要是由于简化导致模型表面几何方向变化和纹理方向变化不一致造成的。算法因此根据几何和纹理方向变化来度量纹理扭曲的程度。可以有效防止简化模型上纹理扭曲的发生，自动快速生成在几何和纹理特征上都保持得较好的简化模型。 |
| Abstract | Polygonal models currently dominate interactive computer graphics. Its simplification and multiresolution representation is an important research topic in computer graphics, especially useful in many applications. The research is conducted on the simplification of this kind of models. A survey of polygonal simplification is given in the second chapter. The error metrics are summarized at first. Then the simplification algorithms are classified according to their underlying reduction mechanisms, and introduction is given particularly to each class in turn. Finally in this chapter, methods used to preserve features on the models simplified are discussed. Today, variety of models is combined with texture images to improve the realism in rendering. We discuss the visual information from texture image and the cause of texture distortion, and then present a simplification algorithm with texture in chapter three. The visual information from different parts of texture image is measured by color variation, and the possibility of texture distortion is measured by the unevenness of texture intensity (the area of a triangle's corresponding texture divided by its area in geometric space). These measurements are combined with geometric metrics, guiding the simplification to produce models with better appearance. In chapter four, we study the solution to prevent the texture distortion in the simplification. By an investigation to various examples, it is found that the texture distortion is mainly produced from the discord of direction variation between texture and surface geometric, incurred by the simplification to the surface. Therefore in the simplification process, we take into account the direction variation between texture and surface geometric as a measurement of texture distortion to control the simplification. As a result, the models simplified can be produced with texture and geometric features preserved well. |
| Pages | 64 |
| Language | 中文 |
| Content Type | 学位论文 |
| URI | http://ir.iscas.ac.cn/handle/311060/6728 |
| Collection | 中科院软件所_中科院软件所 |
| Recommended Citation GB/T 7714 | 郭力真. 结合纹理特征的多边形模型简化算法研究[D]. 中国科学院软件研究所. 中国科学院软件研究所,2004. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| LW014049.pdf（2991KB） | 限制开放 | -- | Application Full Text | |||
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