项目需求：要求圆环外圈毛刺的凸出高度不得超过20像素，如超过判为NG。
算法分析：按照一般的思路，应该是先将外圈拟合成一个圆；然后将这个工件阈值化，提取工件区域；然后用该区域减去之前拟合的圆，剩下的区域就是毛刺部分了。那么什么样特征的毛刺算超标的呢？很显然，如果仅仅用'area'、'inner_radius'等参数去筛选，至少从原理上来看，是不完全契合项目需求的。
具体完整算法如下：
1 read_image (Image, 'C:/Users/02/Desktop/Ring.png')
2 dev_set_draw ('margin')
3 threshold (Image, Region, 0, 253)
4 fill_up_shape (Region, RegionFillUp, 'area', 1, 20000)
5 fill_up (RegionFillUp, RegionFillUp1)
6 difference (RegionFillUp1, RegionFillUp, CircleInner)
7 smallest_circle (CircleInner, Row, Column, Radius)
8 find_circle (Image, PartCircleXLD, Regions, Cross, Circle, Row, Column, Radius + 100, 0, 360, 40, 100, 20, 1, 40, 'negative', 'first', 'inner', 10, 'circle', RowCenter, ColCenter, Radius1)
9 gen_region_contour_xld (Circle, RegionCircle, 'filled')
10
11 *稍微膨胀一下，便于后续处理
12 dilation_circle (RegionCircle, RegionCircle, 1.5)
13 difference (RegionFillUp, RegionCircle,RegionDifference)
14 opening_circle (RegionDifference, RegionDifference, 3.5)
15 connection (RegionDifference, ConnectedRegions)
16 select_shape (ConnectedRegions, SelectedRegions, 'area', 'and', 50, 9999999)
17 count_obj (SelectedRegions, Number)
18
19 *后面精确测量一下多出的毛刺是否超标
20 gen_empty_obj (RegionDefects)
21 if (Number >0)
22 for i := 1 to Number by 1
23 select_obj (SelectedRegions, ObjectSelected, i)
24 distance_pr (ObjectSelected, RowCenter, ColCenter, DistanceMin, DistanceMax)
25 *如果毛刺凸出高度超过20像素，则判断超标
26 if (DistanceMax - Radius1 > 20)
27 concat_obj (RegionDefects, ObjectSelected, RegionDefects)
28 endif
29 endfor
30 endif
31
32 dev_display (Image)
33 dev_display (RegionDefects)
34 disp_cross (3600, RowCenter, ColCenter, 20, 0.45)
与程序中的抓圆函数find_circle相关的函数，可以从这里下载：
https://files.cnblogs.com/files/xh6300/find_line_find_circle.zip