Abstract: A fast antialiasing algorithm，with template matching and curve-fit compensation in image space，is proposed to eliminate the aliasing artifacts such as stairsteps，roundup-tips，and squared-round-corners caused by finite spatial resolution of CRT display and hardcopy devices．Being different from present antialiasing algorithms，it can be used to the image rendered by rastering or scanning the parameter graphics in the same resolution as that of output devices．It has the ability to support parallel processing in pipe line，and is fit to implement with low price hardware net．In addition，its time and space complexity is low ，and the antialiasing result is satisfactory．