一种无人机视频帧自动拼接方法   总被引：1，自引：0，他引：1  

刘善磊  王光辉  石善球  李斌 《测绘科学》2013,38(5):69-71

无人机视频帧具有低对比度和色彩可读性差等缺点,为了解决这些问题并从视频中自动获取视频帧,本文提出一种无人机视频帧自动拼接方法。首先介绍相位相关理论,并推导出指定重叠度视频帧提取公式,在此基础上进行指定重叠度视频帧的自动提取;最后利用改进的SURF算法完成视频帧的匹配和拼接。实验结果表明本文采用的方法能实现视频帧的自动提取和快速拼接。  相似文献   

Rapid texture mapping from image sequences for building geometry model     

Zhang Zuxun  Wu Jun  Zhang Jianqing 《地球空间信息科学学报》2013,16(3):8-15

An effective approach, mapping the texture for building model based on the digital photogrammetric theory, is proposed. The easily-acquired image sequences from digital video camera on helicopter are used as texture resource, and the correspondence between the space edge in building geometry model and its line feature in image sequences is determined semiautomatically. The experimental results in production of three-dimensional data for car navigation show us an attractive future both in efficiency and effect.  相似文献   

A less‐is‐more approach to geovisualization – enhancing knowledge construction across multidisciplinary teams     

Catherine Emma Jones  Mordechai Haklay  Sam Griffiths  Laura Vaughan 《International journal of geographical information science》2013,27(8):1077-1093

The ‘less‐is‐more’ concept in interface design for computer applications has recently gained ground. In this article, the concept is adopted for a user‐centered design of geovisualization application. The premise is that using simple and clear design can lead to successful applications with improved ease of use. Over the last three decades, the development of GIS and geovisualization has seen a marked increase in the levels of interaction between the user, the system and the information. However, these enthusiastic advances in technology have not resulted in a significant increase in the number of users.

This article suggests that types of user interaction should not simply emphasize traditional GIS functions such as zooming and panning but move towards interaction based on facilitating the knowledge construction process. Considerations are made for the complexity of the system, the task at hand and the skills and limitations of the users. These elements are particularly important when maps act as the mediators in collaboration with users across disciplinary backgrounds. In such cases, the emphasis on simplicity and usability becomes as important as functionality. In these situations a geovisualization application designed for specific uses can maximize effective development of geographic knowledge.

In this article, a minimalistic design approach to geovisualization is adopted by creating a geographic profiling tool which shifts the emphasis from technological advances or interaction with the map to the interaction elements key to building the spatial knowledge of GIS experts and non‐experts alike. To evaluate this notion of ‘less‐is‐more geovisualization’ the profiling tool is evaluated according to usability matrices: efficiency, effectiveness and learnability. How well the Suburban Profiler contributes to these elements is assessed by conducting a video analysis of the types and forms of user interaction available. The video analysis demonstrates the usefulness and usability of the Suburban Profiler, providing proof of concept for ‘less‐is‐more geovisualization’.  相似文献   

地理立体视频Web服务框架设计与接口开发     

韩志刚  孔云峰  王震  刘鹏飞 《地球信息科学学报》2013,15(1):97-105

地理立体视频是对视频帧扩展了内外方位元素等地理空间参照的立体视频,支持基于位置的视频查询和影像量测,提供了地理空间表达的一种新形式。随着Web服务技术的广泛应用,地理立体视频Web服务将进一步拓展视频GIS应用。本文重点讨论了地理立体视频Web服务原理和系统设计。通过分析服务功能,设计了由数据层、服务层及表现层构成的地理立体视频Web服务框架;利用REST风格的Web服务技术,从资源确定、URI定义,以及资源操作接口、表述格式等方面进行了服务设计,详细定义了检索服务、视频播放服务,以及影像量测服务接口及其HTTP交互机制,以WCF框架和ArcGIS Server平台实现了相应的服务接口。本文以河南大学金明校区为例,开发了地理立体视频Web服务原型系统并进行了应用实验。结果表明,地理立体视频Web服务实现了可视化、检索及量测等功能,适合于Web环境下视频GIS应用开发,对新型可定位多媒体Web服务的标准化具有参考价值。  相似文献   

Implementation and validation of video monitoring for wood budgeting in a wandering piedmont river,the Ain River (France)     

Bruce MacVicar  Hervé Piégay 《地球表面变化过程与地形》2012,37(12):1272-1289

The transport of wood in rivers during floods is an important process that underlies differences in habitat and morphology between water courses and regions. Quantitative data are needed to properly address management objectives and balance wood budgets. In this study we use a streamside video camera to detect wood passage and measure quasi‐instantaneous rates of wood transport in the Ain River, France. The objectives are to verify the procedure, describe the relation between wood transport and discharge, and construct and validate a wood budget for the reach upstream of the camera. Verification of the procedure includes tests of detection frequency, wood velocity, and piece size. A log base two transformation is proposed to classify wood by piece length. It was found that a wood transport threshold occurs at approximately two thirds of the bankfull discharge. Wood transport follows a positive linear relation with discharge up to the bankfull discharge but is both more variable and less sensitive to discharge when the floodplain is inundated. Transport rates are approximately four times higher on the rising limb of the hydrograph than on the falling limb. Wood transport estimates from a three‐stage rating curve are two to 10 times higher than those from a wood budget using local and aerial surveys of upstream dynamics. Future work should address uncertainties related to wood diameter measurements, sampling length and frequency, and antecedent floods. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

浅谈地震声像科普作品创作元素的运用     

崔磊  刘伟娜  马凤霞 《高原地震》2014,(2):58-63

通过对地震声像科普作品的统计分析,提出了作品中画面、音乐、字幕、图示及动画等方面主要存在的问题和不足之处,对今后如何制作好这类作品提出了建议。  相似文献   

运动视频序列影像的自动配准   总被引：1，自引：1，他引：0  

于文率  余旭初  周俊 《测绘科学技术学报》2006,23(5):348-351

影像配准是运动视频处理应用中的关键技术,从计算机视觉角度出发提出了一种针对运动视频处理的自动影像配准方法.其主要思路可以归结为基于特征匹配的配准过程,具体分为3个方面:利用Harris算子检测角点特征;以互相关函数为测度对角点特征进行初步匹配,特别使用RANSAC拟合基础矩阵F的方法剔除匹配中的错误对应;利用得到的结果重新拟合配准模型进行重采样变换.最后进一步分析了此方法应用于具体运动视频处理时需要考虑的一些问题.  相似文献   

利用小波变换的视频GIS数据数字水印算法     

陈亮  朱长青  任娜  朱一姝 《武汉大学学报(信息科学版)》2012,37(10):1256-1259

提出了一种基于小波变换的视频GIS数据水印算法。该算法结合视频GIS数据特点,将视频流分割为时间轴上连续图像序列。实验结果表明,该算法具有较好的隐蔽性与鲁棒性,并能有效抵抗帧删除、重编码等攻击。  相似文献   

气象影视资料数字化归档管理系统设计与开发   总被引：1，自引：0，他引：1       下载免费PDF全文

张广梅  马东雷  戴思玉  林毅  邹倩倩 《气象与环境学报》2010,26(2):54-57

根据影视资料量大、内容丰富的特点,采用分层式视频资料编目结构,建立气象影视资料数据库,并结合影视素材使用需求,开发了气象影视资料数字化归档管理系统,此系统可以提高气象影视资料的检索速度和影视制作的整体运行效率,并弥补气象影视资料数字化管理的空白。  相似文献   

根据试验视频确定石灰岩中的位移场   总被引：2，自引：0，他引：2       下载免费PDF全文

徐金明  王强  周廷文 《水文地质工程地质》2010,37(2):70-75

根据室内石灰岩抗压强度试验拍摄得到的彩色视频图像与试验数据,使用数字图像相关分析技术,在对原始彩色视频图像进行可读格式转换、灰度变换、傅里叶变换基础上,利用最大相关匹配技术与小变形假设实现了石灰岩视频图像中不同位置相对位移的计算,通过循环计算得到整个石灰岩试样中的位移场与试样中各点位置的变化过程。本文方法对分析岩石变形和破坏机理具有一定的参考价值。  相似文献