opencv检测完美方形形状

Question

i have binary edged image, after applying houghline i have detected all lines in the image, after HoughLines i got following mask image:

after this , i applied convexhull to detect perfect shapes , the binary image i get after applying hull,

在这之后，我尝试应用轮廓，并使用approxPolyDP检测形状，以找到有4个边的形状，这将是正方形或矩形，但是正如我们所看到的，有四个边的形状也被检测为正方形，但我想排除这些形状，任何建议都将不胜感激。在