Silhouette lines are extracted automatically from image,by acquiring points of extremum of first directional derivative perpendicular to silhouette line with Fourier Transform in frequency domain.

• 本文提出通过傅里叶变换,在频率域通过求垂直于物体轮廓线的一阶方向导数,并检测其极值点(极大极小)来确定物体轮廓。