直线检测
直线：[ [[x1,y1,x2,y2]], [[x1,y1,x2,y2]], ... ]
for line in lines:<br> x1, y1, x2, y2 = line[0]<br> cv2.line(img, (x1,y1), (x2,y2), (0,0,255), 2)
圆环检测
圆：[ [[x1,y1,r1], [x2,y2,r2], ...] ]
for c in circles[0]:<br> x, y, r = c<br> cv2.circle(img, (x,y), r, (0,0,255), 3) #绘制圆环<br> cv2.circle(img, (x,y), 2, (0,0,255), 3) #绘制圆心
