標題: 應用於電腦繪圖晶片中之一種新的直線與多邊形之消除鋸齒電路設計與實現
Design and Implementation of a New Antialiasing Line and Polygon for Computer Graphic Chips
作者: 李啟誌
Chi-Chih Li
沈文仁;徐爵民
Wen-Zen Shen;Jyuo-Min Shyu
電子研究所
關鍵字: 消除鋸齒; 電腦圖學; 多邊形;antialiasing; computer graphics; polygon
公開日期: 1994
摘要: 近來由於電腦動畫之流行,電腦繪圖技術常應用於各領域,但傳統的動畫
設計都以繪圖軟體在電腦上製作,在處理大量的 3 維立體圖形物件運算
與著色方面,速度上明顯不足,尤其目前正在發展的虛擬實境系統
(Virtual Reality),因此解決的方法必須利用硬體來製作這些繪圖指令
,才能達到即時(real time)的要求。近年來由於超大型積體電路的快速
發展,使得複雜的三維立體電腦繪圖演算法可以製作成硬體,而將這些硬
體線路製做於一顆晶片中。由於電腦螢幕是數位顯示,在電腦繪圖中,繪
製直線與多邊形的邊緣時,必定會產生鋸齒狀。一般之作法為利用灰階分
配方法,以去除直線的鋸齒現象。本論文提出一新的直線與多邊形消除鋸
齒演算法,此方法改進一最簡單的 "2 點距離" 消除鋸齒演算法,在兩點
之中加入一常數點,使得硬體花費與 "2 點法" 類似,製作上很容易,而
性能可達 "3 點法 " 之效果。並由於這 3 點的灰階分配比值,較其他方
法均勻,使直線看起來更平直,捲繞現象較小,比一般演算法有明顯之改
進。而大部份硬體可直接利用原本繪圖晶片中的直線與混色 (blending)
線路,製作上非常容易。本電路目前已實際應用於工研院電通所之繪圖晶
片,並申請專利權中。
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
顯示於類別:畢業論文