Python Opencv中基礎的知識點

import cv2
import numpy as np
def createWindow():
    #讀取圖片
    img=cv2.imread('images/1 (1).jpg')
    #建立視窗 flags=WINDOW_NORMAL表示可以改變視窗大小
    cv2.namedWindow(winname='window',flags=cv2.WINDOW_NORMAL)
    #縮放視窗的大小
    cv2.resizeWindow(winname='window',width=300,height=200)
    #顯示視窗
    cv2.imshow('window',img)
    #獲取滑鼠或者鍵值
    key=cv2.waitKey(0)
    if (key&0XFF==ord('Q')):
        cv2.destroyAllWindows()
         #銷燬所有的視窗
if __name__ == '__main__':
    print('PyCharm')
    createWindow()

import cv2
import numpy as np
def createWindow():
    #讀取圖片
    img=cv2.imread('images/1 (1).jpg')
    #建立視窗 flags=WINDOW_NORMAL表示可以改變視窗大小
    cv2.namedWindow(winname='window',flags=cv2.WINDOW_NORMAL)
    #縮放視窗的大小
    cv2.resizeWindow(winname='window',width=300,height=200)
    while True:
        #顯示視窗
        cv2.imshow('window',img)
        #獲取滑鼠或者鍵值
        key=cv2.waitKey(0)
        if (key&0XFF==ord('Q')):
            break
        elif (key&0xFF==ord('s')):
            # 儲存圖片
            # name-儲存的檔名 img-儲存的圖片
            cv2.imwrite('save_pic.png', img)
            break
    cv2.destroyAllWindows()
    #銷燬所有的視窗
if __name__ == '__main__':
    print('PyCharm')
    createWindow()

import os
import cv2
import numpy as np
def CollectVideo():
    #建立視窗
    cv2.namedWindow(winname='window',flags=cv2.WINDOW_AUTOSIZE)
    cv2.resizeWindow(winname='window',width=450,height=300)
    #開啟攝像頭
    cap=cv2.VideoCapture(0)
    fourcc = cv2.VideoWriter_fourcc(*'MJPG')
    #獲取視窗大小
    size = (int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)), int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)))
    # 輸出檔案 多媒體檔案格式 視訊影格率  解析度大小
    vw = cv2.VideoWriter('video.avi', fourcc, 25, size)
    while cap.isOpened():
        #從攝像頭讀取視訊幀
        OK,frame=cap.read()
        if OK:
            #顯示攝像頭畫面
            cv2.imshow('window',frame)
            cv2.resizeWindow(winname='window', width=450, height=300)
            #將從攝像頭採集的視訊幀寫入檔案
            vw.write(frame)
        #從滑鼠和鍵盤獲取鍵值,按下ESC鍵退出
        if cv2.waitKey(1)&0xFF==27:
            break
    #釋放資源
    cap.release()
    vw.release()
    #銷燬所有的視窗
    cv2.destroyAllWindows()
if __name__ == '__main__':
    print('Pycharm')
    CollectVideo()

#回撥函數引數解釋
#event：滑鼠移動，按下左鍵；
#（x,y)：滑鼠座標
#flags：滑鼠鍵及組合鍵
import cv2
import numpy as np

#回撥函數定義
def mouse_callback(event,x,y,flags,userdata):
    print(event,x,y,flags,userdata)


#建立視窗
cv2.namedWindow(winname='mouse',flags=cv2.WINDOW_NORMAL)
cv2.resizeWindow(winname='mouse',width=450,height=300)
#給「mouse」視窗設定回撥函數
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鍵退出
    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)
#獲取TrackBar的值
def TrackBarValue():
    #獲取視窗「window」下子視窗「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
#定義TrackBar函數
def TrackBarBGR():
    #value-trackbar的值 count-設定的最大值count（最小值為0） OnChange-回撥函數
    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)
#建立trackbar元件
TrackBarBGR()
while True:
    #獲取trackbar的值
    R,G,B=TrackBarValue()
    img[:]=[B,G,R]
    #獲取值之後改變背景的顏色
    cv2.imshow('trackbar', img)
    #按下ESC鍵退出
    if cv2.waitKey(1)&0xFF==27:
        break
cv2.destroyAllWindows()
if __name__ == '__main__':
    print('Pycharm')