边缘检测,轮廓检测,Sebel算子,高斯拉普拉斯算子,Robert算子,Prewitt算子,Kersch算子等,Hough变换,平行线检测,轮廓提取,种子填充,轮廓跟踪-Edge detection, contour detection, Sebel operator, Gaussian Laplacian, Robert operator, Prewitt operator, Kersch operator, etc., Hough transform, parallel line detec