边标志算法的改进与硬件实现  

Improved edge marking algorithm and its hardware implementation

作　　者：王利祥[1] 肖铁军[1] 

机构地区：[1]江苏大学计算机科学与通信工程学院,江苏镇江212013

出　　处：《计算机工程与设计》2014年第8期2817-2821,共5页Computer Engineering and Design

摘　　要：针对传统的边标志算法在遇到极值点以及狭长条等情况时会出现异常填充的现象,提出一种新的改进方法。充分利用多边形边界光栅化时极值点和狭长条上的点会被重复访问的特点,设置一个计量型标记变量flag,访问到一个像素点时将该像素点的flag值加1,与其它边界点进行区别,以解决上述问题。在Altera公司的cyclone II系列FPGA开发板上进行实现与验证。验证结果表明,该方法填充效果良好,且在系统时钟为33MHz时填充一个像素点仅需0.24ms,在嵌入式图形加速器中具有较高的应用价值。An improved method for traditional edge marking algorithm was proposed, as the traditional one fails to fill an elongated polygon and singular points in the polygon properly. The characteristics that a point on the boundary of the polygon is repeatedly accessed when meeting singular points and elongated points were taken full advantage of, and then a measurement variable flag was set up which was used to mark the boundary point, the flag of the present point was added by 1 when the point was accessed. This method distinguishes local points and elongated points from ordinary points conveniently and simply, so it solves the above problem. Finally, it was implemented and verified by using Altera＇s cyclone Ⅱ development board. The results show that this method fills not only the polygon perfectly, but also a point with 0. 24 ms when the system clock was 33 MHz, so it has high practical value in embedded graphics accelerator.

关 键 词：计算机图形学 边标志算法 多边形填充 现场可编程门阵列 嵌入式图形加速器 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]