目标提取——背景均匀、目标与背景相似

套路：滤波模糊化——动态阈值分割

halcon中案例：surface_scratch.hdev，划痕与背景相似，背景均匀

read_image (Image, 'surface_scratch')
get_image_size (Image, Width, Height)

mean_image (Image, ImageMean, 7, 7) //用7×7的窗口对图像进行均值滤波，获得参考图像
//动态阈值分割
dyn_threshold (Image, ImageMean, DarkPixels, 5, 'dark')  //与参考图像对比，灰度差距5以内可接受，凸显暗色
connection (DarkPixels, ConnectedRegions) //区域拆分
select_shape (ConnectedRegions, SelectedRegions, 'area', 'and', 10, 1000)
union1 (SelectedRegions, RegionUnion) //区域合并，connection的逆过程
dilation_circle (RegionUnion, RegionDilation, 3.5) //圆形膨胀，临近区域联通
skeleton (RegionDilation, Skeleton) //骨架抽取
connection (Skeleton, Errors)
select_shape (Errors, Scratches, 'area', 'and', 50, 10000)
select_shape (Errors, Dots, 'area', 'and', 1, 50)

套路：剔除亮色物——滤波模糊化——动态阈值分割 

halcon中案例：particle.hdev，分析在液体中的颗粒（低亮），目标与背景相似，背景均匀（剔除亮色物后）

read_image (Image, 'particle')
threshold (Image, Large, 110, 255)
dilation_circle (Large, LargeDilation, 7.5)
complement (LargeDilation, NotLarge) //补充，即反色
reduce_domain (Image, NotLarge, ParticlesRed) //缩减预，即二值图转灰度图
mean_image (ParticlesRed, Mean, 31, 31) //均值滤波，模糊化
dyn_threshold (ParticlesRed, Mean, SmallRaw, 3, 'light') //动态阈值分割，取亮色目标
opening_circle (SmallRaw, Small, 2.5)