python opencv鼠标事件实现画框圈定目标获取坐标信息


						本文实例为大家分享了python-opencv鼠标事件画框圈定目标的具体代码，供大家参考，具体内容如下

在视频/相机中，用鼠标画矩形框，圈定目标，从而获得鼠标的起始坐标点a、终止坐标点b





# -*- coding: utf-8 -*-

"""

Created on Tue Dec 27 09:32:02 2016



@author: http://blog.csdn.net/lql0716

"""

import cv2

import numpy as np



current_pos = None

tl = None

br = None



#鼠标事件

def get_rect(im, title='get_rect'): # (a,b) = get_rect(im, title='get_rect')

 mouse_params = {'tl': None, 'br': None, 'current_pos': None,

  'released_once': False}



 cv2.namedWindow(title)

 cv2.moveWindow(title, 100, 100)



 def onMouse(event, x, y, flags, param):



  param['current_pos'] = (x, y)



  if param['tl'] is not None and not (flags & cv2.EVENT_FLAG_LBUTTON):

   param['released_once'] = True



  if flags & cv2.EVENT_FLAG_LBUTTON:

   if param['tl'] is None:

    param['tl'] = param['current_pos']

   elif param['released_once']:

    param['br'] = param['current_pos']



 cv2.setMouseCallback(title, onMouse, mouse_params)

 cv2.imshow(title, im)



 while mouse_params['br'] is None:

  im_draw = np.copy(im)



  if mouse_params['tl'] is not None:

   cv2.rectangle(im_draw, mouse_params['tl'],

    mouse_params['current_pos'], (255, 0, 0))



  cv2.imshow(title, im_draw)

  _ = cv2.waitKey(10)



 cv2.destroyWindow(title)



 tl = (min(mouse_params['tl'][0], mouse_params['br'][0]),

  min(mouse_params['tl'][1], mouse_params['br'][1]))

 br = (max(mouse_params['tl'][0], mouse_params['br'][0]),

  max(mouse_params['tl'][1], mouse_params['br'][1]))



 return (tl, br) #tl=(y1,x1), br=(y2,x2)



#读取摄像头/视频，然后用鼠标事件画框 

def readVideo(pathName, skipFrame): #pathName为视频文件路径，skipFrame为视频的第skipFrame帧

 cap = cv2.VideoCapture(0) #读取摄像头

 if not cap.isOpened(): #如果为发现摄像头，则按照路径pathName读取视频文件

  cap = cv2.VideoCapture(pathName) #读取视频文件，如pathName='D:/test/test.mp4'

 c = 1



 while(cap.isOpened()):

  ret, frame = cap.read()

  gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

  if(c>=skipFrame):

   mask = np.zeros(gray.shape, dtype=np.uint8) #掩码操作，该矩阵与图片大小类型一致，为初始化全0像素值，之后对其操作区域赋值为1即可

   if(c==skipFrame):

    (a,b) = get_rect(frame, title='get_rect') #鼠标画矩形框

    img01, img02 = frame, frame

    gray01, gray02 = gray, gray

   else:

    img1, img2 = prev_frame, frame

    gray1, gray2 = prev_frame, frame

   cv2.imshow('frame', frame)

  c = c + 1

  prev_gray = gray

  prev_frame = frame

  if cv2.waitKey(1) & 0xFF == ord('q'): #点击视频窗口，按q键退出

   break

 cap.release()

 cv2.destroyAllWindows()



以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持中文源码网。