Opencv 入门学习1

import cv2

img = cv2.imread('../samples/c/lena.jpg')
cv2.nameWindow("Image")  #可以不用此句
cv2.imshow("Image",img)
cv2.waitKey(0)  #否则一闪而过
cv2.destroyAllWindows() # 养成关闭的好习惯

import cv2
import numpy as np

img = cv2.imread("../opencv-2.4.9/samples/c/cat.jpg")
emptyImage = np.zeros(img.shape,np.uint8)

emptyImage2 = img.copy()

emptyImage3 = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

cv2.imshow("EmptyImage",emptyImage)
cv2.imshow("Image",img)
cv2.imshow("emptyImage2",emptyImage2)
cv2.imshow("emptyImage3",emptyImage3)
cv2.imwrite("./cat2.jpg",img,[int(cv2.IMWRITE_JPEG_QUALITY),5])
cv2.imwrite("./cat3.jpg",img,[int(cv2.IMWRITE_JPEG_QUALITY),100])
cv2.imwrite("./cat.png",img,[int(cv2.IMWRITE_PNG_COMPRESSION),0])
cv2.imwrite("./cat2.png",img,[int(cv2.IMWRITE_PNG_COMPRESSION),9])
cv2.waitKey()
cv2.destroyAllWindows()