Python Opencv中基础的知识点

目录

• 1.创建窗口
• 2.保存图片
• 3.采集视频
• 4.鼠标控制
• 5.TrackBar组件

import cv2
import numpy as np
def createWindow():
    #读取图片
    img=cv2.imread("images/1 (1).jpg")
    #创建窗口 flags=WINDOW_NORMAL表示可以改变窗口大小
    cv2.namedWindow(winname="window",flags=cv2.WINDOW_NORMAL)
    #缩放窗口的大小
    cv2.resizeWindow(winname="window",width=300,height=200)
    #显示窗口
    cv2.imshow("window",img)
    #获取鼠标或者键值
    key=cv2.waitKey(0)
    if (key&0XFF==ord("Q")):
        cv2.destroyAllWindows()
         #销毁所有的窗口
if __name__ == "__main__":
    print("PyCharm")
    createWindow()

import cv2
import numpy as np
def createWindow():
    #读取图片
    img=cv2.imread("images/1 (1).jpg")
    #创建窗口 flags=WINDOW_NORMAL表示可以改变窗口大小
    cv2.namedWindow(winname="window",flags=cv2.WINDOW_NORMAL)
    #缩放窗口的大小
    cv2.resizeWindow(winname="window",width=300,height=200)
    while True:
        #显示窗口
        cv2.imshow("window",img)
        #获取鼠标或者键值
        key=cv2.waitKey(0)
        if (key&0XFF==ord("Q")):
            break
        elif (key&0xFF==ord("s")):
            # 保存图片
            # name-保存的文件名 img-保存的图片
            cv2.imwrite("save_pic.png", img)
            break
    cv2.destroyAllWindows()
    #销毁所有的窗口
if __name__ == "__main__":
    print("PyCharm")
    createWindow()

import os
import cv2
import numpy as np
def CollectVideo():
    #创建窗口
    cv2.namedWindow(winname="window",flags=cv2.WINDOW_AUTOSIZE)
    cv2.resizeWindow(winname="window",width=450,height=300)
    #打开摄像头
    cap=cv2.VideoCapture(0)
    fourcc = cv2.VideoWriter_fourcc(*"MJPG")
    #获取窗口大小
    size = (int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)), int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)))
    # 输出文件 多媒体文件格式 视频帧率  分辨率大小
    vw = cv2.VideoWriter("video.avi", fourcc, 25, size)
    while cap.isOpened():
        #从摄像头读取视频帧
        OK,frame=cap.read()
        if OK:
            #显示摄像头画面
            cv2.imshow("window",frame)
            cv2.resizeWindow(winname="window", width=450, height=300)
            #将从摄像头采集的视频帧写入文件
            vw.write(frame)
        #从鼠标和键盘获取键值,按下ESC键退出
        if cv2.waitKey(1)&0xFF==27:
            break
    #释放资源
    cap.release()
    vw.release()
    #销毁所有的窗口
    cv2.destroyAllWindows()
if __name__ == "__main__":
    print("Pycharm")
    CollectVideo()

#回调函数参数解释
#event：鼠标移动，按下左键；
#（x,y)：鼠标坐标
#flags：鼠标键及组合键
import cv2
import numpy as np

#回调函数定义
def mouse_callback(event,x,y,flags,userdata):
    print(event,x,y,flags,userdata)


#创建窗口
cv2.namedWindow(winname="mouse",flags=cv2.WINDOW_NORMAL)
cv2.resizeWindow(winname="mouse",width=450,height=300)
#给“mouse”窗口设置回调函数
cv2.setMouseCallback("mouse",mouse_callback,"123")

img=np.zeros(shape=(300,450,3),dtype=np.uint8)
while True:
    cv2.imshow("mouse",img)
    #按下ESC键退出
    if cv2.waitKey(1)&0xFF==27:
        break
cv2.destroyAllWindows()
if __name__ == "__main__":
    print("pycharm")

import os
import cv2
import numpy as np
cv2.namedWindow(winname="trackbar",flags=cv2.WINDOW_NORMAL)
cv2.resizeWindow(winname="trackbar",width=450,height=300)
#获取TrackBar的值
def TrackBarValue():
    #获取窗口“window”下子窗口“R”的值
    value_R=  cv2.getTrackbarPos(trackbarname="R", winname="trackbar")
    value_G = cv2.getTrackbarPos(trackbarname="G", winname="trackbar")
    value_B = cv2.getTrackbarPos(trackbarname="B", winname="trackbar")
    return value_R,value_G,value_B
def callback():
    pass
#定义TrackBar函数
def TrackBarBGR():
    #value-trackbar的值 count-设置的最大值count（最小值为0） OnChange-回调函数
    cv2.createTrackbar("R","trackbar",  0, 255, callback)
    cv2.createTrackbar("G","trackbar",  0, 255, callback)
    cv2.createTrackbar("B","trackbar", 0, 255, callback)
img=np.zeros(shape=(450,300,3),dtype=np.uint8)
#创建trackbar组件
TrackBarBGR()
while True:
    #获取trackbar的值
    R,G,B=TrackBarValue()
    img[:]=[B,G,R]
    #获取值之后改变背景的颜色
    cv2.imshow("trackbar", img)
    #按下ESC键退出
    if cv2.waitKey(1)&0xFF==27:
        break
cv2.destroyAllWindows()
if __name__ == "__main__":
    print("Pycharm")