顾及景深综合的地形素描方法研究

发布时间：2018-04-24 19:16

本文选题：地形素描 + 景深综合　；参考：《南京师范大学》2015年硕士论文

【摘要】：地形素描是以素描写景的形式对自然地表及其形态特征进行的表达,由于其具有简洁性、可读性、抽象性与艺术性的基本特征,成为地理学家描述地表特征,特别是地形地貌特征的有效方式。在摄影技术高度发达的今天,仍得到广泛的应用。传统的地形素描多通过手工绘制所得,随着计算机图形图像技术的发展,已经有学者研究基于侧视影像或数字高程模型数据制作地形素描的方法。但是前人的方法普遍忽略素描中关键问题,即地形素描中存在景深综合问题。地形素描不仅仅是对地形结构特征的有选择性的视觉抽象,作为高度凝练的表达载体,还蕴含了视觉中远近相异的自然综合规律。视觉景深的远近对素描表达的信息量具有决定作用,即越近细节越丰富,越远细节越模糊,即景深综合。如何以计算机数字化的思维去审视与实现地形素描的自动化绘制、有效地表达出地形素描所蕴含的视觉自然综合规律是本研究的重点内容。鉴于此,本研究从形态特征和视觉特征的角度分别对地形素描进行了分析,建立了地形素描特征要素的概念模型,并基于数字高程模型提出了地形素描特征要素的提取算法;分析了人类视觉自然综合的基本规律,定义了地形素描综合的决定因子,并基于地形素描的特点,分别提出了地形素描特征要素的景深综合算法和地形表面的景深综合算法,该景深综合算法均以图形要素的综合为实现方法；开发了基于DEM的地形素描三维场景渲染软件,模拟了三维场景中地形素描的表达与景深综合处理,对模型和算法进行了有效地检验。本研究的主要研究内容及工作包括：1.提出并实现了基于地形骨架线和视觉轮廓线的地形素描算法基于对地形的结构特征分析与视觉特征分析,将地形骨架线作为地形素描的特征要素之一,运用数字地形分析方法进行有效地提取。同时,基于DEM的数据特点和轮廓线的视觉特点,提出了视觉轮廓线的替代性提取算法,使得视觉轮廓线以线结构进行有效的表达。2.提出并实现了基于视觉景深的地形素描综合算法对视觉自然综合的规律进行特征分析,提出了对综合过程具有控制作用的因子,并以此从地形素描特征要素和地形表面这两个角度出发,提出并实现了地形素描的景深综合算法。3.开发了基于DEM的地形素描三维场景渲染软件在VS2013集成开发环境下利用C++程序设计语言,结合图形渲染库OpenGL开发了三维地形素描渲染系统,实现了地形素描特征要素的提取、素描场景的表达和素描的景深综合。
[Abstract]:Topographic sketch is the expression of the natural surface and its morphological characteristics in the form of sketch. Because of its simplicity, readability, abstraction and artistry, it has become a geologist's description of surface features. In particular, the effective manner of landform features. In the photography technology is highly developed today, still get widespread application. With the development of computer graphics and image technology, some scholars have studied the method of making terrain sketch based on side-view image or digital elevation model data. However, the previous methods generally ignore the key problems in sketch, that is, depth of field synthesis in topographic sketch. Topographic sketch is not only a selective visual abstraction of the features of terrain structure, but also a highly condensed expression carrier, and it also contains different natural comprehensive laws in vision. The distance of visual depth of field plays a decisive role in the amount of information expressed by sketch, that is, the closer the details are, the more the details become blurred, that is, the depth of field synthesis. How to use the thinking of computer digitization to examine and realize the automatic drawing of terrain sketch and effectively express the law of visual nature synthesis contained in terrain sketch is the key content of this study. In view of this, this study analyzes the terrain sketch from the angle of the morphological feature and the visual feature, establishes the concept model of the terrain sketch feature element, and puts forward the extraction algorithm of the terrain sketch feature element based on the digital elevation model. This paper analyzes the basic law of natural synthesis of human vision, defines the determinant factor of terrain sketch synthesis, and based on the characteristics of terrain sketch, puts forward the depth of field synthesis algorithm of terrain sketch feature element and the depth of field synthesis algorithm of terrain surface, respectively. The algorithm of depth of field synthesis is based on the synthesis of graphic elements, and a terrain sketch 3D scene rendering software based on DEM is developed, which simulates the representation of terrain sketch and the comprehensive processing of depth of field in 3D scene. The model and algorithm are tested effectively. The main contents and work of this study include: 1. A terrain sketch algorithm based on terrain skeleton line and visual contour line is proposed and implemented. The terrain skeleton line is considered as one of the features of terrain sketch based on the analysis of the structure and visual features of the terrain. The method of digital terrain analysis is used to extract effectively. At the same time, based on the data characteristics of DEM and the visual characteristics of contours, an alternative extraction algorithm of visual contours is proposed, which makes the visual contours express effectively by line structure. A terrain sketch synthesis algorithm based on visual depth of field is proposed and implemented to analyze the characteristics of the law of visual natural synthesis, and the factors that control the synthesis process are put forward. Based on the characteristics of terrain sketch and terrain surface, an algorithm of depth of field synthesis for topographic sketch is proposed and implemented. The terrain sketch 3D scene rendering software based on DEM is developed using C programming language under the VS2013 integrated development environment, and the 3D terrain sketch rendering system is developed in combination with the graphic rendering library OpenGL, which realizes the extraction of terrain sketch feature elements. Sketch scene expression and sketch depth of field synthesis.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P284;P209

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