Question

我正在python中使用openCV库。我要打开图像，单击三个不同的点，然后从中生成一个圆弧段。

单击的第一点是圆的中心。单击的下一个点定义段的起点，单击的最后一个点定义段的终点。

由于cv2.ellipse函数需要角度信息，我对此有点迷茫，我不确定如何从鼠标单击中获取角度信息。

这是我最初的想法：

def draw_circleSegment（事件，x，y，标志，参数）：

global center_pt, upper_pt, center_clicked, upper_clicked

#right mouse click
if event == cv2.EVENT_RBUTTONDOWN:
    #reset
    if center_clicked and upper_clicked:
        center_clicked = False
        upper_clicked = False
        center_pt = (0,0)
        upper_clicked = (0,0)
    #get coordinates of circle center
    if not center_clicked:
        center_pt = tuple(int(el) for el in (x,y))
        center_clicked = True
    #get coordinates of upper point of the circle segment
    if not upper_clicked:
        upper_pt = tuple(int(el) for el in(x,y))
        upper_clicked = True

#initial values of the circle segment
center_pt = (0,0)
upper_pt = (0,0)
center_clicked = False
upper_clicked = False

#capture video
cap = cv2.VideoCapture(r'Path')
cv2.namedWindow(winname='Window Name')
cv2.setMouseCallback('Window Name', draw_circleSegment)

while True: 
    ret_frame, frame = cap.read()

    #draw a circle segment whose points are defined by right mouse click   
    if center_clicked and upper_clicked: 
        cv2.line(frame, center_pt, upper_pt, (255,0,0), 2)
        SegmentAngle=math.degrees(math.atan2(upper_pt[1]-center_pt[1], upper_pt[0]-center_pt[0]))
        radius = int(math.sqrt((upper_pt[0]-center_pt[0])**2 + (upper_pt[1]-center_pt[1])**2))
        cv2.ellipse(frame, center_pt, axes=(radius, radius), angle=SegmentAngle, startAngle=SegmentAngle, endAngle=SegmentAngle+180, thickness=2)
        lower_pt = (upper_pt[0], upper_pt[1]-radius)
            cv2.line(frame, center_pt, lower_ppt, (255,0,0), 2)
        break

因此，在运行此代码时，我收到错误消息“ TypeError：ellipse（）最多包含5个参数（给定7个）”……并且我认为这意味着ellipse的至少一个参数具有错误的类型。这就是为什么我对center_pt和upper_pt和radius都将这些奇怪的转换转换为整数值的原因。但这没有帮助。

有人可以帮忙吗？

OpenCV：如何使用鼠标回调在图像上绘制圆弧段

0 个答案: