open cv学习

1.读取图像

import cv2
img = cv2.imread(r'C:\Users\666\Pictures\Camera Roll\5.jpg')  # 文件位置
cv2.namedWindow("Image")  # 建立窗口
cv2.imshow("Image", img)  # 读取图像
cv2.waitKey(0)  # 正常退出
cv2.destroyAllWindows() #释放窗口
img = cv2.imread(r'C:\Users\666\Pictures\Camera Roll\5.jpg',cv2.IMREAD_GRAYSCALE)#灰度图像
cv2.imwrite('7.jpg', img)#图像保存
cv2.imwrite("cat255541.jpg", img, [int(cv2.IMWRITE_JPEG_QUALITY), 105])#保存大小

2.视频读取

 vc = cv2.VideoCapture(r'G:/G2.mp4')#文件位置
if vc.isOpened():
    open,frame = vc.read()#能否读取

else:
    open = False


while open:
    rct, frame = vc.read()
    if frame is None :
        break
    if rct == True:
        gray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)#灰色处理
        cv2.imshow('Image',gray)
        if cv2.waitKey(10) & 0xff == 27:#关闭方式和帧数
            break
vc.release()#释放内存
cv2.destroyAllWindows()

部分图片截取

 big = img[0:500,0:200]
cv2.namedWindow("Image")  # 建立窗口
cv2.imshow("Image", big) 

颜色截取

b,g,r = cv2.split(img)#拆分
cc=cv2.merge((b,g,r))#合并
cv2.imshow('gg',b)
img[:,:,0]=0
img[:,:,1]=0
cv2.imshow('gg2',img)

边界扩充

top,bot,lefe,right = (50,50,50,50)
replict = cv2.copyMakeBorder(img,top,bot,lefe,right,cv2.BORDER_REPLICATE)
cv2.imshow('gg',replict)
#BORDER_REPLICATE复制法 BORDER_REFLECT反射法 BORDER_REFLECT_101边缘反射法 BORDER_WRAP外包装法 BORDER_CONSTANT,value=0常量法

图像融合

img_1 = cv2.imread(r'C:\Users\666\Pictures\Camera Roll\2.jpg')  # 文件位置
print(img.shape,img_1.shape)#查看行列是否相同
gg=cv2.resize(img_1,(580,580))#把某一个图像行列放大或者缩小至另一个图像大小
res = cv2.addWeighted(img,0.5,gg,0.5,0)#加权融合
cv2.imshow('qq',res)