python - 视频上的 cv2.hough 圆圈错误

Question

当我运行 cv2.HoughCircles() 时出现错误

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

你没有检查你的 circles 是否为 None。如果你这样做，它会起作用:

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]]]