【作者】 陈艳丽；

【导师】 孙群； 李少梅；

【作者基本信息】 解放军信息工程大学 ， 地图制图学与地理信息工程， 2009， 硕士

【摘要】 数字地貌晕渲是在二维平面上显示地势形态起伏的主要方法,随着应用领域逐渐广泛,用户对晕渲图的表现力、艺术性和制作灵活性方面都有了更高的要求。如何在合理准确的塑造各种地貌形态的基础上,提高晕渲的表现力是当前数字地貌晕渲技术面临的主要问题。本文从地貌晕渲法的基本原理出发,针对目前数字晕渲技术存在的问题,结合对地貌特征的分析,研究并实现数字地貌晕渲技术的优化方法。主要内容包括:1.探讨地貌晕渲的基本原理和数字地貌晕渲相关技术。分析晕渲的三个基本原理:几何光学原理、半色调变化原理和空中透视原理在晕渲图制作中的作用;针对不同地貌类型,探讨晕渲所采用的不同地貌塑造方法;总结数字地貌晕渲的相关技术和制作过程。2.通过对地貌形态参数的概念、分类和作用的分析,研究与晕渲相关的地形参数的提取算法;论文通过对不同实验数据的对比,详细分析了不同坡度坡向算法的差异,提出在晕渲图制作中三阶差分算法的适用性较好;通过实验,分析总结不同地貌类型的地形参数特点和变化规律,为了解制图区域地貌类型和数据特点提供依据。3.阐述晕渲技术优化研究的必要性,提出优化研究相关的技术方法。研究主要包括利用地形特征点线的提取算法、缓冲区算法和双线性插值算法研究实现优化范围的确定并保证色调变化的自然过渡;探讨Lambert反射模型和基于坡向的光照模型两种光照模型,分析了它们的差别和各自的优缺点,提出晕渲光照模型的选择方法;通过对地形参数的统计分析合理选择晕渲的光源,归纳总结光源选择可能出现的四种情况;分析色调调整的意义、作用和应用情况等,提出利用坡度、去噪处理划分平地面范围,调整平地面色调的方法。4.应用所研究的晕渲优化技术,编程实现相应的晕渲制作系统,并对系统的功能和利用系统制作晕渲图的基本过程进行介绍。更多还原

【Abstract】 The digital relief shading is the main method that express undulation change of geography appearance on the 2D flat surface, consumers has more need about expressive force, art and agility of relief shading along with the application become more extensive. How can the relief shading figure various topography logically and true, having well expression and achieving high effect is chief problem that the relief shading face.This paper set out from peculiarity of relief shading itself, aims at lack of digital relief shading technique, combines with analysis of geography characteristic, research and realizes optimization for relief shading technique. The main contents include:1. Discussing the rationale of relief shading and technique of digital relief shading. Expatiating three keystones that are the theory for geometric optics, halftone change and aerial perspective. Summarizing different method for showing geography that aims at different geomorphic type. Researching the related technique and making process of digital relief shading.2. Studying the conception, classification and function for topographic parameter, discussing arithmetic of distilling parameters that relate to relief shading. This paper analyses the different arithmetic for slope and aspect particularly, then brings forward Third Order Difference has good applicability in relief shading. Analyzing and summarizing the characteristic and variational rule of topographic parameters for different geomorphic type though experimentation.3. Expatiating the need of researching optimization for relief shading technique, brings forward the method of researching. The main matters include putting out optimization range and assuring the change of color tone naturally by using arithmetic of distilling point and line of geography characteristic, the buffer arithmetic interpolation algorithm; discussing lambert illumination model and model based on aspect, analyzing the difference and excellence themselves, bringing forward the choice for illumination model with relief shading; Choosing the reasonable light source though statistics and analysis of topographic parameter, concluding the four instances may appear about choosing light source; analyzing the meaning, function and application instances of modulating for color tone, bringing forward the method that compartmentalizes flat area and modulates tone of flat area by using slope and disposing yawp.4. Though using techniques researching in optimizing relief shading, establishing the system of making relief shading by programmer, introducing the function of system and the basic process for making relief shading by using system in brief.更多还原