opencv（Python/c++）:直线和圆检测（hough霍夫变换）

墨蓝 2022-03-16 13:28 591阅读 0赞

# Python版 #

*  直线检测

使用的图  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mjc1NTM4NA_size_16_color_FFFFFF_t_70]

import cv2
    import numpy as np
    img=cv2.imread('python.jpg')
    gray=cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
    edges=cv2.Canny(gray,50,120)#注意canny的c是大写啊！！！！！！！
    
    minLineLength=2
    MaxLineGap=5
    
    lines=cv2.HoughLinesP(edges,1,np.pi/180,100,minLineLength,MaxLineGap)
    
    for x1,y1,x2,y2 in lines[0]:
        cv2.line(img,(x1,y1),(x2,y2),(0,0,255),2)
    
    cv2.imshow("edges",edges)
    cv2.imshow('lines',img)
    cv2.waitKey()
    cv2.destroyAllWindows()

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mjc1NTM4NA_size_16_color_FFFFFF_t_70 1]

*  圆检测

import cv2
    import numpy as np
    
    python=cv2.imread('python.jpg')
    gray_img=cv2.cvtColor(python,cv2.COLOR_BGR2GRAY)
    img=cv2.medianBlur(gray_img,5)
    cimag=cv2.cvtColor(img,cv2.COLOR_GRAY2BGR)
    
    circles=cv2.HoughCircles(img,cv2.HOUGH_GRADIENT,1,120,param1=100,param2=30,minRadius=0,maxRadius=0)
    circles=np.uint16(np.around(circles))#uint无符号整型
    
    for i in circles[0,:]:
        #画外部圆
        cv2.circle(python,(i[0],i[1]),i[2],(0,255,0),2)
        #画圆心
        cv2.circle(python, (i[0], i[1]), 2, (0, 0, 255), 3)
    
    cv2.imwrite('python4.jpg',python)
    cv2.imshow('circle',python)
    cv2.waitKey()
    cv2.destroyAllWindows()

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mjc1NTM4NA_size_16_color_FFFFFF_t_70 2]

# c++版 #

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mjc1NTM4NA_size_16_color_FFFFFF_t_70]: /images/20220316/43d7a12d606143febb0e9eafbf044034.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mjc1NTM4NA_size_16_color_FFFFFF_t_70 1]: /images/20220316/94ba5d0839824a8e8724ca7b2ff214f0.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mjc1NTM4NA_size_16_color_FFFFFF_t_70 2]: /images/20220316/b0746f4b74044e15b24e9cb39599d9d4.png