cv2.hough圆形视频错误

Question

当我运行 cv2.HoughCircles() 时，我遇到了一个错误

Traceback (most recent call last):
  File "cv.py", line 1, in <module>
    import cv2,cv
  File "/home/jestinjoy/cv.py", line 19, in <module>
    circles = np.uint16(np.around(circles))
  File "/usr/lib/pymodules/python2.7/numpy/core/fromnumeric.py", line 2277, in around
    return _wrapit(a, 'round', decimals, out)
  File "/usr/lib/pymodules/python2.7/numpy/core/fromnumeric.py", line 37, in _wrapit
    result = getattr(asarray(obj),method)(*args, **kwds)
AttributeError: rint

我的代码是

GNU nano 2.2.6 文件: cv.py

import cv2,cv
import numpy as np

cv2.namedWindow("preview")
vc = cv2.VideoCapture(0)

if vc.isOpened(): # try to get the first frame
    rval, frame = vc.read()
else:
    rval = False

while rval:
        cv2.imshow("preview", frame)
        rval, frame = vc.read()
        img = cv2.medianBlur(frame,5)
        imgg = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
        cimg = cv2.cvtColor(imgg,cv2.COLOR_GRAY2BGR)
        circles = cv2.HoughCircles(imgg,cv2.cv.CV_HOUGH_GRADIENT,1,10,param1=100,param2=30,minRadius=5,maxRadius=20)
        circles = np.uint16(np.around(circles))
        for i in circles[0,:]:
               cv2.circle(cimg,(i[0],i[1]),i[2],(0,255,0),1) # draw the outer circle
               cv2.circle(cimg,(i[0],i[1]),2,(0,0,255),3) # draw the center of the circle
        key = cv2.waitKey(20)
        if key == 27: # exit on ESC
                break
cv2.destroyWindow("preview")

Answer 1

这段代码可能需要一些修改，因为它是两年前问的，可能有些更新了。所以我用ret替代了rval，并且对cv2.HoughCircles的一些属性也做了调整。按q键可以退出。

import cv2
import numpy as np

cv2.namedWindow("preview")
vc = cv2.VideoCapture(0)

if vc.isOpened(): # try to get the first frame
   ret, frame = vc.read()
else:
   ret = False

while True :
   ret, frame = vc.read()
   img = cv2.medianBlur(frame,15)
   imgg = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
   cimg = cv2.cvtColor(imgg,cv2.COLOR_GRAY2BGR)
   circles =   cv2.HoughCircles(imgg,cv2.HOUGH_GRADIENT,1,120,param1=100,param2=30,minRadius=20,maxRadius=200)

   if circles is None:
       cv2.imshow("preview", frame)
       continue
   #circles = np.uint16(np.around(circles))

   for i in circles[0,:]:
      print i
      cv2.circle(frame,(i[0],i[1]),i[2],(0,255,0),1) # draw the outer circle
      cv2.circle(frame,(i[0],i[1]),2,(0,0,255),3) # draw the center of the circle

   cv2.imshow("preview", frame)

   if cv2.waitKey(1) & 0xFF == ord('q'):
       break

vc.release()
cv2.destroyWindow("preview")

Answer 2

Sam说得对，但他的程序没有画出圆圈。这里有一个修复的方法：

import cv2
import numpy as np

cv2.namedWindow("preview")
vc = cv2.VideoCapture(0)

if vc.isOpened(): # try to get the first frame
    rval, frame = vc.read()
else:
    rval = False

while rval:
    cv2.waitKey(1)
    rval, frame = vc.read()
    img = cv2.medianBlur(frame,5)
    imgg = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
    cimg = cv2.cvtColor(imgg,cv2.COLOR_GRAY2BGR)
    circles = cv2.HoughCircles(imgg,cv2.cv.CV_HOUGH_GRADIENT,1,10,param1=100,param2=30,minRadius=5,maxRadius=20)

    if circles is None:
        cv2.imshow("preview", frame)
        continue
    #circles = np.uint16(np.around(circles))

    for i in circles[0,:]:
       print i
       cv2.circle(frame,(i[0],i[1]),i[2],(0,255,0),1) # draw the outer circle
       cv2.circle(frame,(i[0],i[1]),2,(0,0,255),3) # draw the center of the circle

    cv2.imshow("preview", frame)

    key = cv2.waitKey(20)

    if key == 27: # exit on ESC
        break

cv2.destroyWindow("preview")

Answer 3

你没有检查一下你的 circles 是否是 None。如果你加上这个检查，代码就能正常运行了：

import cv2
import numpy as np

cv2.namedWindow("preview")
vc = cv2.VideoCapture(0)

if vc.isOpened(): # try to get the first frame
    rval, frame = vc.read()
else:
    rval = False

while rval:
        cv2.imshow("preview", frame)
        cv2.waitKey(1)
        rval, frame = vc.read()
        img = cv2.medianBlur(frame,5)
        imgg = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
        cimg = cv2.cvtColor(imgg,cv2.COLOR_GRAY2BGR)
        circles = cv2.HoughCircles(imgg,cv2.cv.CV_HOUGH_GRADIENT,1,10,param1=100,param2=30,minRadius=5,maxRadius=20)
        if circles is None:
                continue
        print circles
        #circles = np.uint16(np.around(circles))
        for i in circles[0,:]:
               cv2.circle(cimg,(i[0],i[1]),i[2],(0,255,0),1) # draw the outer circle
               cv2.circle(cimg,(i[0],i[1]),2,(0,0,255),3) # draw the center of the circle
        key = cv2.waitKey(20)
        if key == 27: # exit on ESC
                break
cv2.destroyWindow("preview")

生成的输出：

sam@tuwien:/tmp$ python cv.py 
VIDIOC_QUERYMENU: Invalid argument
VIDIOC_QUERYMENU: Invalid argument
VIDIOC_QUERYMENU: Invalid argument
VIDIOC_QUERYMENU: Invalid argument
VIDIOC_QUERYMENU: Invalid argument
VIDIOC_QUERYMENU: Invalid argument
VIDIOC_QUERYMENU: Invalid argument
[[[ 335.5         368.5          10.12422848]]]
[[[ 334.5         386.5          10.12422848]]]
[[[ 349.5         382.5          10.12422848]]]
[[[ 392.5         365.5          10.12422848]]]
[[[ 378.5         370.5          10.12422848]]]
[[[ 378.5         368.5          12.34908867]]]
[[[ 391.5         369.5          14.57738018]]]
[[[ 379.5         370.5          10.12422848]]]