首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
To use graphics efficiently in an automatic report generation system, one has to model messages and how they go from the writer (intention) to the reader (interpretation). This paper describes PostGraphe, a system which generates a report integrating graphics and text from a set of writer's intentions. The system is given the data in tabular form as might be found in a spreadsheet; also input is a declaration of the types of values in the columns of the table. The user then indicates the intentions to be conveyed in the graphics (e.g., compare two variables or show the evolution of a set of variables) and the system generates a report in LATEX with the appropriate PostScript graphic files. PostGraphe uses the same information to generate the accompanying text that helps the reader to focus on the important points of the graphics. We also describe how these ideas have been embedded to create a new Chart Wizard for Microsoft Excel. Received 20 August 1998 / Revised 2 September 1999 / Accepted 27 September 1999  相似文献   

2.
采用元胞自动机方法建立生物陶瓷降解和新骨生长的仿真模型,运用可视化技术对仿真结果进行图形化和动画显示.实验表明,只要模型的控制参数输入比较正确,仿真模型可以在不同阶段对降解的材料和新生的骨组织作定量分析.  相似文献   

3.
针对动画卡通形象的特点,选取典型卡通形象范例,并分割出范例图元形成图元库。利用傅里叶形状描述方法统一描绘用户输入草图和范例图元的轮廓特征,用输入草图的特征检索图元库,得到相似的范例图元,通过交互方式调整和修改图元,进而生成个性化的卡通形象。实验结果表明,该方法生成的卡通形象基本符合用户的设计意图。  相似文献   

4.
The logical input device model, as is adopted in the standardized graphics package GKS, has been an accepted basis for producing device-independent graphics systems. However, when used in highly interactive graphical applications, the logical input device model does not provide sufficient support for a number of fundamental issues inherent to interaction. This paper reopens a discussion which questions the functionality provided by the logical input device model when brought in conjunction with interaction. In particular, the logical input device model does not support the notion of input/output symmetry. CR Categories: 1.3.4 [Computer graphics]: Graphics utilities- graphics packages; 1.3.6 [Computer graphics]: Methodology and techniques- device independence, interaction techniques  相似文献   

5.
针对传统fuzzing测试中的低效率问题,提出一种基于污点跟踪的黑盒fuzzing测试方法.通过将合法输入标记为污染源,并记录污点在应用程序中的传播过程,提取关键的污点信息,用以指导新的测试用例的生成.这样生成的测试用例,具有更好的针对性,以及能够达到较深的代码深度,有良好的代码覆盖率,能更好的挖掘出潜在的漏洞和安全脆弱点.采用这种方法对几款图形处理软件和图形库进行了测试,发现了一个漏洞,并提交SecurityFocus通过.  相似文献   

6.
Inverse Procedural Modelling of Trees   总被引:1,自引:0,他引:1  
Procedural tree models have been popular in computer graphics for their ability to generate a variety of output trees from a set of input parameters and to simulate plant interaction with the environment for a realistic placement of trees in virtual scenes. However, defining such models and their parameters is a difficult task. We propose an inverse modelling approach for stochastic trees that takes polygonal tree models as input and estimates the parameters of a procedural model so that it produces trees similar to the input. Our framework is based on a novel parametric model for tree generation and uses Monte Carlo Markov Chains to find the optimal set of parameters. We demonstrate our approach on a variety of input models obtained from different sources, such as interactive modelling systems, reconstructed scans of real trees and developmental models.  相似文献   

7.
Bézier representations have been widely employed as a standard way of designing complex scenes with very good quality results. These surfaces are usually tessellated, in the software application, into triangle models to be rendered. Then, the final image is generated in the graphics card so that its triangle rendering capabilities are exploited.In this work we present an adaptive tessellation algorithm and the corresponding architecture to be implemented in hardware. The objective of the proposal is to avoid the potential bottleneck associated with the transmission of complex triangular models from CPU to graphics cards. The algorithm we propose is based on a layer strip representation method and a new data management that permits generation and efficient storage of the tessellated mesh. The corresponding architecture has to be included as an additional unit at the input of the graphics card. As a consequence, the transmission requirements from CPU to graphics card are greatly reduced as the tessellation is performed in the graphics card. On the other hand, the adaptive strategy employed permits selection of the number of triangles of the final mesh as a trade off between computational requirements and quality of the final mesh. The efficient data management proposed, together with the low storage requirements of the architecture, makes it a good candidate for its hardware implementation and inclusion in future graphics cards.  相似文献   

8.
This overview introduces the emerging set of techniques for parsing and generating multiple media (e.g., text, graphics, maps, gestures) using multiple sensory modalities (e.g., auditory, visual, tactile). We first briefly introduce and motivate the value of such techniques. Next we describe various computational methods for parsing input from heterogeneous media and modalities (e.g., natural language, gesture, gaze). We subsequently overview complementary techniques for generating coordinated multimedia and multimodal output. Finally, we discuss systems that have integrated both parsing and generation to enable multimedia dialogue in the context of intelligent interfaces. The article concludes by outlining fundamental problems which require further research.  相似文献   

9.
This paper describes the generation and rendering of three‐dimensional (3D) surface cellular automata (CA). Our model's main advantage is that it gives direct texturing simulation based on the actual shape of any triangulated input object. We first introduce general CA concepts and summarize works in the literature. We then describe our 3D surface CA method, emphasizing how it avoids potential problems in data structure and rendering steps. We then detail, two examples of specific 3D surface CA with their respective cell structures and corresponding computer graphics images. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

10.
We provide an overview of two multimedia generation systems developed at Columbia University, COMET and MAGIC, and analyze them using the standard reference model for intelligent multimedia presentation systems. COMET (Coordinated Multimedia Explanation Testbed) emphasizes the coordinated generation of text and 3D graphics in a military maintenance and repair documentation domain. It features support for automated determination of what information to present, assignment of information to appropriate media and generation of textual cross-references to the structure and content of generated graphics, including the automated redesign of graphics to make possible better cross-references. MAGIC (Multimedia Abstract Generation for Intensive Care) generates presentations that use temporal media, including speech and animation, to explain the status of hospital patients. It extends the media coordination approach used in COMET to include a multi-stage negotiation process that solves temporal constraints imposed by individual media generators to determine when and for how long actions should occur in each medium.  相似文献   

11.
This paper describes the specification of an input model for graphics systems. The initial aim of the work reported in this paper was to revise the input model adopted by graphics standards by means of formal specification techniques in order to acquire a deep knowledge of its capabilities, to eventually discover errors and to develop improvements. Taking into account similar works done in this area by others and considering a number of major issues related to input recently discussed within the graphics community, a new model is being proposed that addresses the very key concepts of parallelism, extensibility and reconfigurability. The model is based upon composition operations defined over basic components specified as a set of concurrent processes. Composition operations and process definitions have been formally specified by using the LOTOS notation and investigated by means of the LOTOS Interactive Tools Environment. In the first part of the paper, the input model of graphics standards is shortly examined in the light of the results so far achieved by related works on formal specification of computer graphics systems. Subsequently, an improved model is presented. Finally, its capability of simulating the traditional operating modes of logical input devices and a methodology for defining new operating modes is demonstrated.  相似文献   

12.
该文提出了用分形技术来自动生成复杂雕刻图形的基本方法,并分别介绍了基于集合分形、函数分形与随机分形的雕刻图形的自动生成过程,分析了分形函数生成雕刻图形的影响因素,论述了通过映射实现由二维分形雕刻图形向三维雕刻图形转换的基本原理。通过分析可得,分形技术是实现复杂雕刻图形自动生成的重要途径之一,在雕刻艺术中,分形技术有广泛的应用前景。  相似文献   

13.
The automatic generation of realistic vegetation closely reproducing the appearance of specific plant species is still a challenging topic in computer graphics. In this paper, we present a new approach to generate new tree models from a small collection of frontal RGBA images of trees. The new models are represented either as single billboards (suitable for still image generation in areas such as architecture rendering) or as billboard clouds (providing parallax effects in interactive applications). Key ingredients of our method include the synthesis of new contours through convex combinations of exemplar countours, the automatic segmentation into crown/trunk classes and the transfer of RGBA colour from the exemplar images to the synthetic target. We also describe a fully automatic approach to convert a single tree image into a billboard cloud by extracting superpixels and distributing them inside a silhouette-defined 3D volume. Our algorithm allows for the automatic generation of an arbitrary number of tree variations from minimal input, and thus provides a fast solution to add vegetation variety in outdoor scenes.  相似文献   

14.
A look at the trends in computer graphics is given by analyzing important areas that affect the progress of graphics like hardware, input and output devices for graphics, programming languages, systems developments and advances in techniques and algorithms for computer graphics. Then attention is given to new and expanded application areas for the future, as well as some problems that will persistently confront people working in graphics.  相似文献   

15.
In the present-day graphics field, a proper methodology for designing input constructs of a general purpose graphics system is needed. In this direction, this paper proposes a framework where the graphics interaction programming is formulated as event-driven procedures. The end-user actions on the input tools are represented as events and the programreactions to these events as action-processes. The constructs for programming in this framework are implemented as a part of a graphics package SODDI. The resultant programming facilities are compared with the other existing proposals, based on the conceptual differences of the respective frameworks as well as on the experiences in using the constructs. The data-structures used for implementing these constructs are also presented.  相似文献   

16.
This paper describes a facsimile-based graphics editing system using handwritten mark recognition, and presents some experimental results with the system. In a manner different from usual graphics editors based on CRT displays and data tablets, only facsimiles are used as input and output devices in this system. As the first stage in processing, a graphic subject is first given as a set of line drawings and characters handwritten on a sheet of paper, and it is then input into the computer as a binary picture from a facsimile transmitter. Auxiliary editing information is input into the computer as handwritten marks or seal marks prepared on a separate sheet of paper. As the second stage, the marks are recognized and used to create a mark parameter list for the graphics editing. Third, referencing the mark parameter list, the graphics are expressed by using a set of graphic commands, and edited by the computer. Finally, a correct edited copy of the graphics is constructed by picture processing based on graphic commands, and it is output to a facsimile receiver. Very good results have been obtained for various kinds of hand-written graphics by using the system described here.  相似文献   

17.
A spatial relation graph (SRG) and its partial matching method are proposed for online composite graphics representation and recognition. The SRG-based approach emphasizes three characteristics of online graphics recognition: partial, structural, and independent of stroke order and stroke number. A constrained partial permutation strategy is also proposed to reduce the computational cost of matching two SRGs, which is originally an NP-complete problem as is graph isomorphism. Experimental results show that our proposed SRG-based approach is both efficient and effective for online composite graphics recognition in our sketch-based graphics input system - SmartSketchpad.Received: 13 March 2003, Accepted: 13 March 2004, Published online: 1 June 2004  相似文献   

18.
When graphics input/output capabilities are added to a programming language originally designed with a text stream input/output model, various design decisions affect the ease with which the graphics facilities are learned and used by applications programmers. In adding window system facilities to the Icon programming language, some design decisions were made very differently from the conventional wisdom, resulting in substantial benefits for programmers. In addition, some pre-existing Icon language features have proved to be useful in graphics programming.  相似文献   

19.
复杂草图识别是手绘草图输入中的一个困难任务。现存的草图识别方法强调的是图形对象简单.但这不适合具有不同复杂性的复杂草图的识别。本文对具有不同复杂性的复杂图形对象提出一个基于图形的统一表示法,文中根据不同信息枉度将复杂图形分别转化为空间关系图(SRG)。文中提出了一个约束的部分枚举.以减小识别复杂草图时匹配SRG的状态空间。实验结果显示.我们的方法可适用于具有不同复杂度的各种复杂图形对象的识别。  相似文献   

20.
《Computers & chemistry》1989,13(2):129-139
Chemical Abstracts Service (CAS) has developed complex computer-based systems for the registration and retrieval of chemical substance information. This paper focuses on the data structures and computer graphics software used to represent and process graphical representations of chemical substance information. At CAS the representation of graphical data is standardized and is referred to as the CAS Graphical Data Structure (GDS). The GDS is used for the input and display of chemical structures in the CAS-developed Messenger® search and retrieval software. Messenger software is used to operate the online information retrieval service called STN International®, the scientific and technical information network. STN International provides scientists and information specialists with online access to many different scientific and technical databases. In particular, STN provides access to the CAS ONLINE® Registry File, which currently contains over 8.8 million records of unique chemical substances. This paper surveys the current structure graphics components of the Messenger software. These components provide online structure input and structure display capabilities for the CAS ONLINE Registry File. This paper also introduces the capabilities of a new Personal Computer (PC)-based software package called STN Express™. The software includes an offline structure input capability specifically developed for structure query formulation by scientists and information specialists. Possible future extensions to the CAS structure graphics software are also addressed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号