基于视觉感知拓扑关系模型的作战编队可视化

针对传统的作战编队可视化中作战队形缺少刻画、背景对比不突出、整体感不强、美学性不足等问题,提出了作战编队的可视化基本原则。依据可视化基本原则,建立了作战编队的视觉感知拓扑关系模型,该模型通过采用图算法叠加处理,解决了作战编队中个体之间连接关系的选择优化难点,给出了一个连接关系总数的上限估计函数,较好地刻画了作战编队的视觉整体范围及内部个体关联性等抽象信息,根据连接关系构建出的连线具有交叉少、拟合队形等优良的可视化特征。基于视觉感知拓扑关系模型,构建了作战编队的三维可视化(3DCFV)算法。实验结果显示：连线数目平均减少了37%;无连线交叉;连线拟合队形等,与传统相比,整体的可视化效果提升显著。     

Visual Debugging Techniques for Reactive Data Visualization

Interaction is critical to effective visualization, but can be difficult to author and debug due to dependencies among input events, program state, and visual output. Recent advances leverage reactive semantics to support declarative design and avoid the “spaghetti code” of imperative event handlers. While reactive programming improves many aspects of development, textual specifications still fail to convey the complex runtime dynamics. In response, we contribute a set of visual debugging techniques to reveal the runtime behavior of reactive visualizations. A timeline view records input events and dynamic variable updates, allowing designers to replay and inspect the propagation of values step‐by‐step. On‐demand annotations overlay the output visualization to expose relevant state and scale mappings in‐situ. Dynamic tables visualize how backing datasets change over time. To evaluate the effectiveness of these techniques, we study how first‐time Vega users debug interactions in faulty, unfamiliar specifications; with no prior knowledge, participants were able to accurately trace errors through the specification.     

Data Visualization: Featuring Interactive Visual Analysis

Data visualization is an application‐driven field, that is always trying to satisfy its customers and to adapt to the demands, cultures, and workflows of many application areas. Therefore, it is difficult to keep focus on techniques and approaches that are not too application specific. A lot of good work on data visualization consists of single‐problem solutions, that cannot be easily merged into general‐purpose systems. In this talk, I will briefly review some current trends and issues, and identify some approaches that are common to many applications. One such approach in data visualization that has attracted interest from the early days is the detection of salient features, or patterns of interest in a data set. The main idea is to extract information at a higher level of abstraction from a mass of data, that is richer in semantics but much smaller in size, and that can help to define scenes and objects for visualization. This idea was pioneered in areas such as flow visualization, but is now more widely applied. It is often considered to be necessity to keep up with the ever rapidly increasing size of data sets, and the demand for interactivity in data visualization and analysis. Another generic approach in data visualization is called interactive visual analysis (TVA), consisting of a strongly interactive multiple‐linked‐view interfaces with integrated, powerful data analysis techniques taken from statistical analysis, pattern recognition, machine learning, and other fields. This is built on the assumptions that a single 2D or 3D visualization is often not enough, and spatial views can be augmented with abstract, derived data spaces; that strong interaction helps to promote insight; and that a better balance is needed between human visual inspection and computer‐based analysis and reasoning. Interestingly, an IVA interface can serve not only as an environment for exploration of low‐level data, but also for defining the high‐level features to be extracted, that should summarize the essence of the data. The high‐level features are usually highly application specific, and can only be found using theories from the application domains. The big challenge is to create environments for general purpose visual data analysis, and yet allow users to introduce advanced theories and methods from many application domains. The trend towards more integration in data visualization will be illustrated with cross‐links between very different areas, such as medical and flow visualization, and the combined use of techniques from scientific visualization and information visualization, and the absorption of other data analysis techniques. Also, historic and contemporary examples of feature extraction and interactive visual analysis will be shown.     

The Role of Structure and Content in Perception of Visual Similarity Between Web Pages

In human–computer interaction, users' perception of visual similarity in interfaces may affect how well they judge the relevance of information, construct appropriate mental models, and effectively interact with computers. This is of interest to both computer science and psychology. A review of the theoretical and applied research in visual similarity reveals both a content-oriented and a structural-oriented approach. The present study seeks to understand the content and structural aspects of visual similarity judgment. Unlike early theoretical studies in psychology, web pages were used as realistic stimulus in an experimental study. Structural and content changes to pairs of web pages were incrementally applied in experimental sessions while participants were judging the similarity of these pairs. The results of the experiment indicated that similarity ratings between two pages correlate negatively with the number of alterations made to the layout of one of the pages. Similarity ratings between two pages also declined when distinctive background colors were applied to one of the pages. The experiment also revealed that text-complete web pages received lower similarity ratings than wire frames of the pages. Pages with readable text received higher similarity ratings than pages with unreadable text. The results of this study will help web designers produce web pages of various similarities that will be consistent with users' judgment and help improve similarity-based web researches.     

虚拟环境中的视觉感知

通过对现实世界,平面图像的视觉成象方式的比较,指出虚拟环境成象方式是二者相结合的产物。在论述虚拟环境所提供的视差对三维深度感知重要性的同时,结合视觉生理特点,分析总结了虚拟环境所具有的缺陷,即违背了视标所发出的入瞳光线的散开度与双眼所处的状态应该相辅相成这一规律,提出了虚拟环境给队造成头晕、眼睛疲劳等不良反应的根源是虚拟对象容易使双眼的辐辏和调节功能发生冲突。最后列举并分析了刷新延迟、分辩率、瞳距等各种可能给观察者带来不良反应的诸多因素。     

Visual Narrative Flow: Exploring Factors Shaping Data Visualization Story Reading Experiences

Many factors can shape the flow of visual data‐driven stories, and thereby the way readers experience those stories. Through the analysis of 80 existing stories found on popular websites, we systematically investigate and identify seven characteristics of these stories, which we name “flow‐factors,” and we illustrate how they feed into the broader concept of “visual narrative flow.” These flow‐factors are navigation input, level of control, navigation progress, story layout, role of visualization, story progression, and navigation feedback. We also describe a series of studies we conducted, which shed initial light on how different visual narrative flows impact the reading experience. We report on two exploratory studies, in which we gathered reactions and preferences of readers for stepper‐ vs. scroller‐driven flows. We then report on a crowdsourced study with 240 participants, in which we explore the effect of the combination of different flow‐factors on readers’ engagement. Our results indicate that visuals and navigation feedback (e.g., static vs. animated transitions) have an impact on readers’ engagement, while level of control (e.g., discrete vs. continuous) may not.     

融合本体理论的电网动态威胁数据模型与可视感知

网络安全威胁可视化,深度融合网络状态和攻击形式,将网络中安全态势感知与可视化技术结合,实现全域网络可信状态下受到威胁的可视化表征.电力数据网络威胁可视化技术仍存在传统数据模型的表征能力受限以及状态特征冗余和离散导致表达可用程度低的问题.本文提出了融合本体理论与态势演变的电网动态威胁网格化可视感知,通过设计实体化的三阶段统一攻击威胁行为模型,有效解决了电力数据网络安全特征表征模糊问题.设计基于本体特征的深度内容检测方法,形成电网安全数据的紧密关系特征集,从而降低了状态特征的冗余程度,精细化处理后的网络威胁数据将通过态势阶梯,实现攻击行为的图形表征平滑渐变.通过贵州省遵义市供电局电网威胁可视化实验,验证本文方法提升网络安全威胁监测错误4%.     

Visual Perception in Realistic Image Synthesis

Realism is often a primary goal in computer graphics imagery, and we strive to create images that are perceptually indistinguishable from an actual scene. Rendering systems can now closely approximate the physical distribution of light in an environment. However, physical accuracy does not guarantee that the displayed images will have authentic visual appearance. In recent years the emphasis in realistic image synthesis has begun to shift from the simulation of light in an environment to images that look as real as the physical environment they portray. In other words the computer image should be not only physically correct but also perceptually equivalent to the scene it represents. This implies aspects of the Human Visual System (HVS) must be considered if realism is required. Visual perception is employed in many different guises in graphics to achieve authenticity. Certain aspects of the visual system must be considered to identify the perceptual effects that a realistic rendering system must achieve in order to reproduce effectively a similar visual response to a real scene. This paper outlines the manner in which knowledge about visual perception is increasingly appearing in state‐of‐the‐art realistic image synthesis. After a brief overview of the HVS, this paper is organized into four sections, each exploring the use of perception in realistic image synthesis, each with slightly different emphasis and application. First, Tone Mapping Operators, which attempt to map the vast range of computed radiance values to the limited range of display values, are discussed. Then perception based image quality metrics, which aim to compare images on a perceptual rather than physical basis, are presented. These metrics can be used to evaluate, validate and compare imagery. Thirdly, perception driven rendering algorithms are described. These algorithms focus on embedding models of the HVS directly into global illumination computations in order to improve their efficiency. Finally, techniques for comparing computer graphics imagery against the real world scenes they represent are discussed.     

视觉计算--人类感知能力的延伸

从２０世纪５０年代开始,计算机开始被作为实现人工智能和人类感知的工业,借助计算机,人类第一次可以像借助机械实现对体力的延伸一样实现对脑力和感知能力的延伸。从６０年代初开始,围绕计算机视觉进行了大量的研究。本文回顾了近４０年来计算机视觉研究的进展情况,对其中一一些重要进展包括立体视觉、从各种线索恢复开头以及运动分析主主动视觉等主流技术和方法进行了综述,对计算机视觉技术的主要应用进行了概括。在分析了这     

可视化系统DVS中图的局部放大功能实现原理解析

在基于可视化软件包VTK开发的数据可视化系统DVS中,新增图的局部放大功能。采用依据选择区域相对于视区的位置和大小决定相机位置,从而实现局部放大。在界面处理过程中,尝试用实时替换VTK的事件处理函数方法来解决VTK不能处理鼠标移动事件的缺陷,设计实现了橡皮筋选择方式。结果表明在软件开发的过程中灵活地使用外部方法可弥补某些应用软件包的功能不足。     

基于视觉感知的图像放大

为了有效保持图像纹理细节和边界结构,提出了一种基于视觉感知的图像放大算法。构造了一类[C2]连续的双变量有理函数插值模型。根据等值线生成原理,利用等值线方法将图像自适应地划分为边缘区域和平滑区域。基于图像的区域特征,平滑区域采用多项式模型插值,边缘区域采用有理模型插值。根据人眼对比敏感特性,对边缘区域进行参数优化,从而获得高质量插值图像。与其他经典的图像放大方法相比,该方法能有效保持图像的纹理细节和边缘结构,同时获得了较好的客观评价数据。     

The Role of Visual Fidelity in Computer-Based Instruction

New digital video technologies provide a wide spectrum of multimedia interface capabilities for educational courses running on personal computers. A formal experiment was conducted using a digital video course on code inspection to determine the effects of such capabilities on recall performance and attitude. The findings suggest that the presentation of material as motion video rather than as a slide show within an interactive video course leads to better recall performance. In addition, the presence of motion video in the interfaces and the use of surrogate travel for navigation promote better student opinions toward the subject matter.     

激光体积测量中散乱数据的可视化

在激光体积测量应用中,测量数据往往为三维散乱数据,实现其可视化,还原测量对象的外形与轮廓有着重要的意义.文章使用按距离平方反比加权插值与按方位取点加权插值相结合的方法,实现了测量数据的插值,应用趋势面拟合的方法重构,使曲面更光滑,并提出程序结束判断算法,实际应用表明该方法是可行的.     

Visualization Mosaics for Multivariate Visual Exploration

We present a new model for creating composite visualizations of multidimensional data sets using simple visual representations such as point charts, scatterplots and parallel coordinates as components. Each visual representation is contained in a tile, and the tiles are arranged in a mosaic of views using a space‐filling slice‐and‐dice layout. Tiles can be created, resized, split or merged using a versatile set of interaction techniques, and the visual representation of individual tiles can also be dynamically changed to another representation. Because each tile is self‐contained and independent, it can be implemented in any programming language, on any platform and using any visual representation. We also propose a formalism for expressing visualization mosaics. A Web‐based implementation called MosaicJS supporting multidimensional visual exploration showcases the versatility of the concept and illustrates how it can be used to integrate visualization components provided by different toolkits.     

无人系统的视觉感知安全研究

随着现代科技的不断革新,以机器学习尤其是深度学习为代表的人工智能技术正在改变无人系统的发展,推动无人作战等作战形态快速演变,对未来战争带来颠覆性影响。然而由于深度学习的不可解释性、脆弱性等问题,人工智能技术在现实应用中产生了诸多不确定性和安全风险。本文聚焦人工智能技术在军事无人系统中的安全问题,从视觉感知的角度出发,重点分析了安全风险来源、对抗样本理论和视觉感知对抗攻击方法和防御对策,最后对无人系统领域人工智能应用的安全问题进行了总结。     

Python在数据可视化中的应用

数据可视化是许多科研领域的关键环节。当前有很多可视化工具,如Origin、Sigmaplot、Matlib等。这些工具有很多是商业化的软件,并不具备数据统计分析能力。本文介绍一种基于Python的新兴的、免费的可视化方法。Python更接近人类的自然语言,易学,并且具有强大的数据爬取、预处理、统计分析、挖掘和可视化功能,在网络爬虫、大数据、云计算、人工智能等众多领域都有广泛应用。本文首先介绍了Python语言的特点,然后介绍常用可视化库,并通过示例来展示用Python做可视化的优势。     

Predicting Visual Perception of Material Structure in Virtual Environments

One of the most accurate yet still practical representation of material appearance is the Bidirectional Texture Function (BTF). The BTF can be viewed as an extension of Bidirectional Reflectance Distribution Function (BRDF) for additional spatial information that includes local visual effects such as shadowing, interreflection, subsurface‐scattering, etc. However, the shift from BRDF to BTF represents not only a huge leap in respect to the realism of material reproduction, but also related high memory and computational costs stemming from the storage and processing of massive BTF data. In this work, we argue that each opaque material, regardless of its surface structure, can be safely substituted by a BRDF without the introduction of a significant perceptual error when viewed from an appropriate distance. Therefore, we ran a set of psychophysical studies over 25 materials to determine so‐called critical viewing distances, i.e. the minimal distances at which the material spatial structure (texture) cannot be visually discerned. Our analysis determined such typical distances typical for several material categories often used in interior design applications. Furthermore, we propose a combination of computational features that can predict such distances without the need for a psychophysical study. We show that our work can significantly reduce rendering costs in applications that process complex virtual scenes.