标题: 应用于电脑绘图晶片中之一种新的直线与多边形之消除锯齿电路设计与实现
Design and Implementation of a New Antialiasing Line and Polygon for Computer Graphic Chips
作者: 李启志
Chi-Chih Li
沈文仁;徐爵民
Wen-Zen Shen;Jyuo-Min Shyu
电子研究所
关键字: 消除锯齿; 电脑图学; 多边形;antialiasing; computer graphics; polygon
公开日期: 1994
摘要: 近来由于电脑动画之流行,电脑绘图技术常应用于各领域,但传统的动画
设计都以绘图软体在电脑上制作,在处理大量的 3 维立体图形物件运算
与着色方面,速度上明显不足,尤其目前正在发展的虚拟实境系统
(Virtual Reality),因此解决的方法必须利用硬体来制作这些绘图指令
,才能达到即时(real time)的要求。近年来由于超大型积体电路的快速
发展,使得复杂的三维立体电脑绘图演算法可以制作成硬体,而将这些硬
体线路制做于一颗晶片中。由于电脑萤幕是数位显示,在电脑绘图中,绘
制直线与多边形的边缘时,必定会产生锯齿状。一般之作法为利用灰阶分
配方法,以去除直线的锯齿现象。本论文提出一新的直线与多边形消除锯
齿演算法,此方法改进一最简单的 "2 点距离" 消除锯齿演算法,在两点
之中加入一常数点,使得硬体花费与 "2 点法" 类似,制作上很容易,而
性能可达 "3 点法 " 之效果。并由于这 3 点的灰阶分配比值,较其他方
法均匀,使直线看起来更平直,卷绕现象较小,比一般演算法有明显之改
进。而大部份硬体可直接利用原本绘图晶片中的直线与混色 (blending)
线路,制作上非常容易。本电路目前已实际应用于工研院电通所之绘图晶
片,并申请专利权中。
Since the display method of computer monitor is digital, it
will show jaggy(aliasing) phenomenon when drawing lines and
polygon edges. The normal method for antialiasing is to use
various gray level for each pixel to eliminate the jaggy
phenomenon. In this thesis, we have presented a new
antialiasing line and polygon algorithm. This method is
induced from the simplest "2-pixel" antialiasing algorithm by
inserting a constant pixel between these two pixels. So, the
hardware is comparable to "2-pixel" algorithm and is easy to
implement. Besides, the proportion of gray-value of the three
pixels is more even, so the antialiasing line looks more
smooth and is lightly curl. Meanwhile, the performance is
comparable to "3-pixel" algorithm, and is better than the
other existing algorithms. In hardware implementation, we can
use some circuits for line-drawing and blending in a graphic
chip to fulfill most of the hardwares of this circuit. Thus,
we need only a few extra hardware. This circuit is now applied
in ITRI CCL graph ic chip and is filing for pattern.
URI: http://140.113.39.130/cdrfb3/record/nctu/#NT830430111
http://hdl.handle.net/11536/59305
显示于类别:Thesis