Secondly we use canny arithmetic operators to get the edge of image , and remove the short link of edge then link the edge with small clearance . at last we can calculate the distance of conductor and the width of conductor according to the grade direction to detect of defect of the circuit boards 然后选用canny算子提取导线边缘，并对边缘进行短分支去除和边缘连接处理，最后根据梯度方向来计算导线间距离和导体宽度，以此来判断电路板缺陷。
These properties make them ideal candidates for use in structure from motion algorithms . some known methods of line segment are integrated and an improved method is given . canny edge detector is used in this method to get edge , link the edge using freeman chain code , and then gradually delete useless chain code 首先综合边缘直线分割的研究成果，给出了改进后的边缘直线分割方法，该方法以图像边缘的链码表示为基础，逐步删除对完成计算机视觉任务没有意义的链码，并用最小二乘法拟合成图像直线。
Based on these algorithms , and consider the property of the arc image , we proposed a new multi - stage algorithm . the proposed algorithm involves the class separability criterion in pattern recognition , and double - threshold method and non - maximum suppression proposed in canny operator . we apply this algorithm to the arc image , and get a better result 并在这些算法的基础上，基于电弧图像的特点，提出了一种改进的多阶段边缘检测算法，这个算法中应用到模式识别中的类别可分离判据的理论，并使用了canny算法所中提出的双阈值法和非极大值抑制方法等等。
After studied for several decades , there have appeared several classical edge operators , such as roberts , sobel , laplacian , canny and log . meanwhile , there also have presented several classical algorithms of image restoration , such as inverse filter , wiener filter and constrained least squares filter 经过多年的研究,已经形成了roberts算子、 sobel算子、 laplacian算子、 canny算子、 log算子等经典的边缘检测算子以及逆滤波、维纳滤波、约束最小二值滤波等经典的图像恢复方法。
There are many methods of edge detection . according to practical task , we choose some classical methods of edge detection including first differential ( roberts operator , sobel operator and prewitt operator ) , second differential ( laplacian operator and kirsch operator ) , log filter and canny operator . they are studied in theory and practice applying 边缘检测有很多方法，根据课题实际背景，选择了几种比较经典的边缘检测方法，即一阶算子( roberts算子、 sobel算子、 prewitt算子) 、二阶算子( laplacian算子和kirsch算子) 、 log算子和canny算子，对他们进行理论和实际应用研究。
Although various mechanics models have put forward many numerical techniques , the widely used one that is commonly admitted by engineers is the finite element method . combined the joint elements , on some extent this method could overcome structural surface obstacles described by the mechanics of continuous media such as the joint of canny existing in the inner of rocks . until now , the finite element method has been widely employed because of the mature of the large - scale construction computing software 针对各种力学模型提出了多种数值方法,最广泛使用的并获得了工程界普遍承认的是有限元法,有限元法结合节理单元可以一定程度上克服连续介质力学在描述岩体内部存在节理裂隙等结构面的障碍,目前有限元法由于大规模结构计算软件的成熟而为工程界所普遍运用。
