Python + OpenCV =如何裁剪圓？

Question

下面是代碼：

self.img = cv2.imread(image,) 
circle = cv2.HoughCircles(self.img, 3, 
          dp=1.5, minDist=1000, minRadius=100, maxRadius=1000) 
red = (0,0,255) 
x = circle[0][0][0] 
y = circle[0][0][1] 
r = circle[0][0][2] 
cv2.circle(self.img, (x, y), r, red, 2) 



    x - X 
    y - Y 
    r - Radius 
    For example: 521.25, 506.25, 318.919 

從代碼如何裁剪從給定的例子圓？

Answer 1

它的簡單..你需要得到矩形的右上角的x，y座標，並找到與高度。圈子只能以正方形包圍。

# given x,y are circle center and r is radius 
rectX = (x - r) 
rectY = (y - r) 
crop_img = self.img[y:(y+2*r), x:(x+2*r)] 

Answer 2

後圈= cv2.HoughCircles（IMG，...）

if len(circles) == 1: 
    x, y, r = circles[0][0] 
    print x, y, r 
    mask = np.zeros((w0,h0),dtype=np.uint8) 
    cv2.circle(mask,(x,y),r,(255,255,255),-1,8,0) 
    #cv2.imwrite(argv[2],mask) 
    out = img*mask 
    white = 255-mask 
    cv2.imwrite(argv[2],out+white)