Question

我是opencv -python的新手。我想在从我的网络摄像头捕获的直播视频中绘制一个矩形。绘制矩形时，视频必须冻结。我成功地在图像上绘制了一个矩形，但我不知道如何使用opencv和python在实时视频上做同样的事情。请帮忙..

Answer 1

这是我用来在视频中绘制矩形的代码。

代码就是这样的：

点击视频，脚本保存起点
再次单击，脚本保存结束点并绘制矩形

再次点击开始绘制另一个视角

import numpy as np
import cv2

rect = (0,0,0,0)
startPoint = False
endPoint = False

def on_mouse(event,x,y,flags,params):

    global rect,startPoint,endPoint

    # get mouse click
    if event == cv2.EVENT_LBUTTONDOWN:

        if startPoint == True and endPoint == True:
            startPoint = False
            endPoint = False
            rect = (0, 0, 0, 0)

        if startPoint == False:
            rect = (x, y, 0, 0)
            startPoint = True
        elif endPoint == False:
            rect = (rect[0], rect[1], x, y)
            endPoint = True

cap = cv2.VideoCapture('../videos/sample.avi')
waitTime = 50

#Reading the first frame
(grabbed, frame) = cap.read()

while(cap.isOpened()):

    (grabbed, frame) = cap.read()

    cv2.namedWindow('frame')
    cv2.setMouseCallback('frame', on_mouse)    

    #drawing rectangle
    if startPoint == True and endPoint == True:
        cv2.rectangle(frame, (rect[0], rect[1]), (rect[2], rect[3]), (255, 0, 255), 2)

    cv2.imshow('frame',frame)

    key = cv2.waitKey(waitTime) 

    if key == 27:
        break

cap.release()
cv2.destroyAllWindows()

使用Opencv和python在实时流上单击鼠标事件

1 个答案: