To test the implemented OCR system for Chinese characters, a very large number of handwritten Chinese character samples are required. The collecting work is time consuming and strenuous. In this paper, we present a new method for generating handwritten Chinese character samples. We introduce an algebra of geometric shapes, the geometric shapes have composite operations such as Fourier addition and Fourier multiplication. In our method, a small set of Chinese character samples are required. We use Fourier series descriptor to describe the shape of these specific Chinese characters. Handwritten Chinese character samples with various styles may be generated automatically by the following methods. (1) Changing the harmonics N of Fourier series. (2) With the Fourier addition operation, a random shape may be added to the shape of the existing Chinese character. (3) Combining styles of two or more kinds of handwritten Chinese character samples. Experiment result shows that our method is effective.
Recent interest in large displays has led to the development of a variety of multi-screen display systems, most of which are comprised of multiple projectors situated for front or rear projection onto a screen to form a large logical display, and each projector is driven by one PC, augmented with high-performance graphics accelerator card. However, most of these systems are immediate-mode based, that is, all geometry data and control information must be sent on the run, and thus the interconnecting network bandwidth between clients and servers has become a fatal bottleneck. In this paper, we describe MSPR, a retained-mode based multi-screen parallel rendering system which offers the programmers with a OpenGL-like API. And the system could be run locally on one PF or parallelly rendered among any number of Computers. The details of data distribution, load balance, interconnecting network architecture, tile mosaic, etc. are hidden from the programmers.
Computer graphics has become an important discipline in both academia and industry, and an enabling technology for a broad variety of applications such as engineering (CAD, CAE and CAM), geographic information systems (GIS), publishing, office applications, games and the filmmaking industry. Graphics is also integrated to Internet application systems, and graphics and image techniques are combined together in some special applications. Computer graphics can no longer be regarded as a confined discipline devoted solely to graphics standards or traditional techniques of 3D representations and rendering. The influence of computer graphics and its related techniques can be felt in almost all of today's key industrial areas, wherever computers are employed.Computer graphics has been a subject of interest in China for many years. Primary overviews of computer graphics activities in China were presented in [9] (on research and industry) and [8] (on education). In addition, there was also a special journal issue on computer graphics in China [10]. However, computer graphics activities in Hong Kong [7] and Macao were not included in these materials. Furthermore some new achievements were achieved in the past years. For example, in the State Key Lab of CAD&CG, Zhejiang University, a four-sided CAVE was installed in 1999. In addition, nowadays virtual reality (VR) is a hot research topic. In China researchers have attained many achievements in various VR fields. We will emphasize this aspect as we introduce computer graphics activities in China.This article gives an overview of the research and development of computer graphics in China, including the mainland of China, Hong Kong and Macao. The article is organized as follows. The next section introduces computer graphics research in some major universities and institutes in China. The section following that presents some industrial activities in computer graphics in China. The next section presents some other activities related to computer graphics. The final section gives closing comments.
We propose a new method for finding similarity in 3-D protein structure comparison. Different from the other existing methods, our method is grounded in the theory of fractal geometry. The proposed feature vectors of protein structures are simple to implement. The method is very fast because it requires neither alignment of the chains nor any chain-chain comparison. We calculate the fractal features of a set of 200 protein structures selected from PDB(Protein Data Bank). The experimental result shows that our method is very effective in classification of 3-D protein structures.
In many applications of scientific visualization, the data fields are so large that they are very expensive to store, transmit and render. Multiresolution offers a promising new approach for addressing these difficulties on a simple, unified way. Wavelets provide an extremely useful mathematical toolkit for hierarchically decomposing functions in ways that are both efficient and theoretically sound. This paper focuses on extension of wavelet based multiresolution to arbitrary topological data grid. Using wavelet transform, the method proposed here obtains a unique shape description of an irregular data field. A biorthogonal volume wavelet is constructed. Recursive subdivision is applied to irregular data field and leads to a collection of refinable scaling functions and hence to a sequence of nested linear spaces, as required by multiresolution. In order to overcome the subdivision connectivity restriction, an applicable method is presented to convert the completely arbitrary data field to multiresolution so that the technique for creating multiresolution can be used.
There are two problems in the existing rendering platforms that support HLA-based simulation applications. One is the fact that the management of simulation entity objects and the management of rendering scene objects are separate, which leads to inefficiency in simulation and rendering. Another one is absence of rendering interface, especially for parallel rendering for users. In order to solve the above problems, we present a unified object model supporting HLA-based simulation and parallel rendering, which consists of heterogenous scene graph tree, action list and universal access interface. The Unified object model establishes an efficient data exchange bridge between HLA simulation and parallel rendering. Therefore massive complex scene and large quantity of simulation entities can be organized and managed in a unified form. An experimental demo is given at the end of this paper.
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