python版opencv入门（1）
读入图片
cv2.imread()
第一个参数：图片名
第二个参数：
• cv2.IMREAD_COLOR : Loads a color image. Any transparency of image will be neglected. It is the default
flag.
• cv2.IMREAD_GRAYSCALE : Loads image in grayscale mode
• cv2.IMREAD_UNCHANGED : Loads image as such including alpha channel
Note: Instead of these three flags, you can simply pass integers 1, 0 or -1 respectively.
1 import numpy as np 2 import cv2 3 img = cv2.imread('test.jpg',0) #显示一张灰度图
显示图片
cv2.imshow()
1 cv2.imshow('image',img) 2 cv2.waitKey(0) 3 cv2.destroyAllWindows()
写入图片
cv2.imwrite()
1 cv2.imwrite('test.png',img)
打开图片，处理并保存的整个流程
1 import numpy as np 2 import cv2 3 img = cv2.imread('test.jpg',0) 4 cv2.imshow('image',img) 5 k = cv2.waitKey(0) 6 if k == 27:# wait for ESC key to exit 7 cv2.destroyAllWindows() 8 elif k == ord('s'): # wait for 's' key to save and exit 9 cv2.imwrite('testgray.png',img) 10 cv2.destroyAllWindows()
