opencv画框返回坐标 python_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()
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