使用python在open cv中进行圆圈检测

Question

我试图用红色圆形物体检测黑色背景中的圆圈.

import cv2
import cv2.cv as cv
import numpy as np

img = cv2.imread('extracted.jpg',0)
img = cv2.medianBlur(img,5)
cimg = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

circles = cv2.HoughCircles(img,cv.CV_HOUGH_GRADIENT,1,20,
                        param1=50,param2=30,minRadius=0,maxRadius=0)

circles = np.uint8(np.around(circles))
for i in circles[0,:]:
   # draw the outer circle
   cv2.circle(cimg,(i[0],i[1]),i[2],(0,255,0),2)
   # draw the center of the circle
   cv2.circle(cimg,(i[0],i[1]),2,(0,0,255),3)

cv2.imshow('detected circles',cimg)
cv2.waitKey(0)
cv2.destroyAllWindows()

我已经以灰度模式加载了图像,但它仍然给我一个错误

"circles = np.uint8(np.around(circles))
File "/usr/lib/python2.7/dist-packages/numpy/core/fromnumeric.py", line 2277, in around
  return _wrapit(a, 'round', decimals, out)
File "/usr/lib/python2.7/dist-packages/numpy/core/fromnumeric.py", line 37, in _wrapit
  result = getattr(asarray(obj),method)(*args, **kwds)
AttributeError: rint"

由于我目前的声誉,我无法发布图片.

Answer 1

您的代码中有一个小的更正.

您正在以灰度加载图像,然后再次将其转换为灰度,使用cv2.cvtColor无效操作.

或者,OpenCV 使用Hough Circles方法提供用于圆检测的样本.你可以试试.

如果您使用的是OpenCV 2.x版本,只需更改您喜欢的cv2.LINE_AAto cv2.CV_AA或任何其他lineType.