一、说明
halcon中取区域边缘的算子很多，但是哪个效果更好，本文比较edges_image和edges_sub_pix进行对比
二、edges_image的示例代码
read_image (Image, 'D:/images/taps/gtape')
edges_image (Image, ImaAmp, ImaDir, 'lanser2', 0.5, 'nms', 12, 22)
threshold (ImaAmp, Edges, 1, 255)
skeleton (Edges, Skeleton)
gen_contours_skeleton_xld (Skeleton, Contours, 1, 'filter')
dev_display (Image)
dev_set_colored (6)
dev_display (Contours)三、 edges_sub_pix函数
read_image (Image, 'D:/images/taps/gtape')
*
* Init window
get_image_size (Image, Width, Height)
dev_open_window (0, 0, Width, Height, 'black', WindowHandle1)
*
* Segment a region containing the edges
fast_threshold (Image, Region, 0, 140, 7)
boundary (Region, RegionBorder, 'inner')
* clip_region_rel (RegionBorder, RegionClipped, 5, 5, 5, 5)
dilation_circle (RegionBorder, RegionDilation, 2.5)
reduce_domain (Image, RegionDilation, ImageReduced)
*
* In the subdomain of the image containing the edges,
* extract subpixel precise edges.
set_color(WindowHandle1, 'green')
*'deriche1', 'lanser1', 'deriche2', 'lanser2', 'shen', 'mshen', 'canny', 'sobel', and 'sobel_fast'
edges_sub_pix (ImageReduced, Edges, 'lanser2', 2, 20, 60)四、结果分析
用edges_image的结果：
edges_sub_pix的结果：
可以看出，上边红线只是包络边缘，可以判定不能达到亚像素级别；edges_sub_pix的边缘横跨黑白之间，达到亚像素测量，edges_sub_pix测量时要好。
