外文翻译--字符的计算机处理与显示

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1、  PDF外文：http:/    本科毕业设计（论文）     外 文翻译          年     级： 2004 级  学     号： 20041235 姓     名：任 XXX 专     业：机械设计制造及其自动化  指导老师：           2008 年  06 月外 文翻译     &nbs

2、p;                     第 1 页    英文翻译  1 英文  ON COMPUTERISATION AND REPRESENTATIONOF CHARACTERS The commercial need to computerise contours of objects has intensified over recent years as more and more applications endeavour to see

3、k the benefits of visualisation. The primary aim has been  to gain a computerised model which closely resembles the original shape and form. The digital form lends itself to be  processed  by  fast processors, and  their output to  be  displayed on  graphic de

4、vices such as screen displays and  laser printers. The benefits of the digital form are also extended to cater for numerically controlled machines. These are employed to produce outlines through  cutting or  engraving on  paper, metal, plastic or wood. When it comes to digitling

5、the outlines of characters, additional considerationshave to be included in the modelling, design, phase. The aim of these is to capture the uniqueness and the distinct features of a font, which traditionally were realised by a proficient artisans hand and eye. Modern approaches endeavour to gain th

6、e same impact by using a set of pre-defined specifications in the design process. The goal of which is not just to model accurately a desired font, but also to ensure that the displayed version is both legible and aestheticallyacceptable. This paper provides an insight about the design methods used

7、to both model and represent the contours of Latin characters and fonts. It describes the role of the spline as a means of realising the modelling aspect. To this regard, the spline descriptions used  by  Postscript (BCzier cubic) and  TrueType (parabolic) are looked at, and a comparat

8、iveanalysis made. The discussion throughout is levelled at providing a practical understanding of the subject matter. 1.0 Introduction The quest for an accurate and aesthetically acceptable representation of outlines of shape has traditionally been undertaken by experienced artisans. They produced d

9、esired results by using a skilled hand, having an  eye for fine detail and an appreciation of the type and form of the shape itself. This process of generating outlines found  popularity in the field of typography, where an exact production and reproduction of contours of characters is req

10、uired. The task for the typographer was not just to draw a given outline, but also to 外 文翻译                           第 2 页    capture the distinct features of a particular font type. This manual process of modelling characte

11、r outlines becomes rather tedious and time-consuming when one realises that there are thousands of Latin font types available, each comprisingof at least 100 characters. With the arrival of computers, attempts have been made to automate the design process.This has resulted in software programs under

12、 the headings of computer-aided-design (CAD), manufacture (CAM) and geometric-design (CAGD) being developed. The modem typographer uses a particular design package to capture and model a desired font. The process works with some pre-defined specifications,ensuring that the modelled image embodiesthe

13、 desired font features. In view of modem commercial requirements for a fast and accurate means of computerising a given outline,  most  design systems make use of a  mathematical description. This has the  attraction, when compared to the manual approach, of providing a modelled

14、image at a faster rate and yielding within,  and  between,  design systems. In addition, the resulting image is in a form which can be transformed  (translated, rotated, scaled Ftc) without distortion by using a simple and an  appropriated matrix. The simplest mathematical d

15、escription makes use of straight line segments from point to point around the outline. An example of the approach is depicted in Fig 1. Clearly, it can be seen that the resulting model gives a coarse representation of the original. More data points and thus line segments will be required to yield th

16、e desired  outcome. Even then, it is not certain whether the resulting representation would be acceptable for aesthetic reasons.  Another shortcoming with the line modelling approach is the amount of  continuity it gives  between joining segments. As it stands, the system can at most provide zero