Python错误集锦：OpenCV HoughCircles找圆时提示One of the arguments’ values is out of range) dp, min_dist and canny_threshold must be all positive numbers in function ‘cv::HoughCircles’

原文链接：http://www.juzicode.com/python-error-opencv-arguments-values-out-of-range-dp-mindist-cannythreshold-must-be-all-positive-numbers-houghcircles

错误提示：

使用HoughCircles找圆时提示modules\imgproc\src\hough.cpp:2257: error: (-211:One of the arguments’ values is out of range) dp, min_dist and canny_threshold must be all positive numbers in function ‘cv::HoughCircles’

#VX公众号: 桔子code / juzicode.com
import numpy as np
import cv2  
print('cv2.__version__:',cv2.__version__)
img_src = cv2.imread('opencv-logo.png',0) 
circles = cv2.HoughCircles(img_src,cv2.HOUGH_GRADIENT,dp=1,minDist=-20,param1=50,param2=30,minRadius=0,maxRadius=0)
print('circles.shape:',circles.shape)
print('circles:\n',circles)

==========运行结果：
---------------------------------------------------------------------------
error                                     Traceback (most recent call last)
<ipython-input-6-86e4886547c2> in <module>
      4 print('cv2.__version__:',cv2.__version__)
      5 img_src = cv2.imread('opencv-logo.png',0)
----> 6 circles = cv2.HoughCircles(img_src,cv2.HOUGH_GRADIENT,dp=1,minDist=-20,param1=50,param2=30,minRadius=0,maxRadius=0)
      7 print('circles.shape:',circles.shape)
      8 print('circles:\n',circles)

error: OpenCV(4.5.3) E:\juzicode\opencv-4.5.3\modules\imgproc\src\hough.cpp:2257: error: (-211:One of the arguments' values is out of range) dp, min_dist and canny_threshold must be all positive numbers in function 'cv::HoughCircles'

错误原因：

1、使用HOUGH_GRADIENT方法时，dp，minDist，param1参数必须大于0

解决方法：

1、minDist参数改设置为大于0的数值

#VX公众号: 桔子code / juzicode.com
import numpy as np
import cv2  
print('cv2.__version__:',cv2.__version__)
img_src = cv2.imread('opencv-logo.png',0) 
circles = cv2.HoughCircles(img_src,cv2.HOUGH_GRADIENT,dp=1,minDist=20,param1=50,param2=30,minRadius=0,maxRadius=0)
print('circles.shape:',circles.shape)
print('circles:\n',circles)

==========运行结果：
cv2.__version__: 4.5.3
circles.shape: (1, 22, 3)
circles:
 [[[143.5 415.5 141.2]
  [297.5 139.5  54.7]
  [451.5 414.5 135.7]
  [160.5 403.5 161.7]
  [472.5 417.5 123.4]
  [ 61.5 644.5  60.7]
  [346.5 665.5  44.4]
  [161.5 426.5 117.3]
  [445.5 436.5 115.1]
  [445.5 645.5  61.5]
  [404.5 672.5  83.8]
  [170.5 662.5  41.2]
  [248.5 650.5  36.6]
  [452.5 665.5  61.2]
  [132.5 438.5 115.4]
  [ 44.5 624.5  39.6]
  [ 42.5 656.5  47.9]
  [ 56.5 672.5  67.8]
  [469.5 646.5  62.1]
  [442.5 625.5  60. ]
  [421.5 656.5  46.2]
  [245.5 672.5  35.2]]]

扩展内容：

1. OpenCV-Python教程

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