点击鼠标在视频中鼠标位置绘制固定矩形(python_opencv)

Question

所以在我 webcam/video 期间，我想当我单击鼠标时，在鼠标位置绘制一个矩形，并且矩形大小是固定的。 80 X 80。在我当前的代码中，矩形跟随鼠标，但大小始终不同。当我点击视频中的帧时，我想要一个固定的大小正好在鼠标位置。

这是我的代码。

import os
import numpy as np
import cv2 
from PIL import Image
import re



print('kaishi')
flag=0
drawing = False

point1 = ()
point2 = ()
ref_point = []
xvalues=[];
yvalues=[];
ref_point = []


cx=0;
cy=0;
 def mouse_drawing(event, x, y, flags, params):
     global point1, point2, 
     drawing,ref_point2,flag,refPt,cropping,cx,cy



     if event == cv2.EVENT_LBUTTONDOWN:

        drawing = True
        point1 = (x, y)
        xvalues.append(x)
        yvalues.append(y)
        cx =x;
        cy=y;


elif event == cv2.EVENT_MOUSEMOVE:
    if drawing is True:
        point2 = (x, y)




elif event == cv2.EVENT_LBUTTONUP:
        flag+=1;
        print('finished square')





cap = cv2.VideoCapture(0)

cv2.namedWindow("Frame")
cv2.setMouseCallback("Frame", mouse_drawing)


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

      if point1 and point2 :
        cv2.rectangle(frame,(200,cy),(cx,128),(0,0,255),0)
        print(cx,cy)

        flag=0;





    cv2.imshow("Frame", frame)

key = cv2.waitKey(25)
if key== 13:

    print('done')




elif key == 27:
     break



 cap.release()
 cv2.destroyAllWindows()

Answer 1

问题是你固定了矩形的一个点，另一个点跟随鼠标。在您的代码中，它将位于此处：

cv2.rectangle(frame,(200,cy),(cx,128),(0,0,255),0)

现在就看长方形如何了，你点击的那个点是左上角的那个点吗？如果是那么它应该是这样的：

cv2.rectangle(frame,(cx,cy),(cx + 80, cy +80),(0,0,255),0)

此示例适用于 80 x 80 矩形...。在您的代码中，单击时会发生这种情况。

但是，您的代码有很多未使用的代码...我会这样做：

import numpy as np
import cv2 

drawing = False
point = (0,0)

def mouse_drawing(event, x, y, flags, params):
     global point, drawing
     if event == cv2.EVENT_LBUTTONDOWN:
        drawing = True
        point= (x, y)

cap = cv2.VideoCapture(0)
cv2.namedWindow("Frame")
cv2.setMouseCallback("Frame", mouse_drawing)

while True:
   _, frame = cap.read()
   if drawing :
      cv2.rectangle(frame,point,(point[0]+80, point[1]+80),(0,0,255),0)

   cv2.imshow("Frame", frame)
   key = cv2.waitKey(25)
   if key== 13:    
     print('done')
   elif key == 27:
     break

 cap.release()
 cv2.destroyAllWindows()

如果您希望矩形在您单击后跟随您的鼠标并在您释放按钮后停止跟随，请更改我在 mouse_drawing 函数之前提供的代码，如下所示：

def mouse_drawing(event, x, y, flags, params):
     global point, drawing
     if event == cv2.EVENT_LBUTTONDOWN:
        drawing = True
        point = (x, y)
     elif event == cv2.EVENT_MOUSEMOVE:
       if drawing is True:
        point = (x, y)
    elif event == cv2.EVENT_LBUTTONUP:
        drawing = False
        point = (x, y)

点击鼠标在视频中鼠标位置绘制固定矩形(python_opencv)

Click mouse and draw fixed rectangle at mouse position in Video (python_opencv)

python

video

opencv

cv2