V型焊缝图像处理中阈值自动选取的一种算法

Arithmetic of threshold selected automatically for image processing of arc-V-shape weld seam

介绍了V型焊缝图像识别中一种阈值自动选取的算法及其实现。该算法选取一个5×5窗口区域,在这个窗口中制作4个五边形、4个六边形、1个正方形共9种形状的滑动窗口模板。5×5窗口以列的形式在图像上滑动时分别计算每个窗口区域内灰度值的方差,然后找出最大方差,同时获取方差最大区域内的平均灰度值。依此方式获取每列方差最大的区域,相应的便可获得每列方差最大处的灰度平均值,最后选取所有灰度平均值中最大的一个作为阈值。通过对陆地上焊接各种焊缝图像和水下焊接V型焊缝图像的处理效果表明,该算法可用于V型焊缝中心点的提取。

An arithmetic of threshold selected automatically for image processing of arc-v-shape weld seam is introduced.The arithmetic designs a window region including five rows pixels and five columns pixels ,and in these pixels designing four kinds of pentagon which are made up of five pixels and four kind of hexagon which are also made up of six pixels and a square which arc also made up of five pixels,all kinds of shapes added up to nine.After these,getting variances of gray-scale in every region of different shapes through calculating, and finds the maximum in these variances, meanwhile ,getting the average gray-scale in this region whose variance is maximum.It can obtain the region whose variance is maximum in different columns using this method,and obtain the average gray- scale in this region every column at the same time.At last,selecting the maximum one in these all average gray-scales as threshold.All kinds of weld seams collected on the land and Arc-v-shape weld seams collected underwater when robots weld in water are dealled with by this method, which proves that this method can use in the comics of gelling the characteristic dots of arc-v-shape weld seam images.