opencv&python - basic

opencv basic operations (using cv2 module):

• read image
• get the image size
• show image
• move image window to the specified position
• save image
• convert the color space

01 from cv2 import *02 
03 # read image
04 # imread() returns the image as a NumPy array
05 # the image is stored in BGR order!
06 '''
07     flags-
08         CV_LOAD_IMAGE_GRAYSCALE - always convert image to the grayscale one
09         CV_LOAD_IMAGE_COLOR - always convert image to the color one
10         CV_LOAD_IMAGE_ANYDEPTH - load the image as is
11 '''
12 im = imread("lena.jpg")
13 print(type(im))
14 
15 # image info
16 height, width, channel = im.shape
17 print(height, width, channel)
18 # or for a grayscale image
19 #height, width = im.shape
20 
21 # show image
22 namedWindow("lena")
23 imshow("lena", im)
24 
25 # move window to the specified position
26 # cv2.moveWindow(winname, x, y)
27 moveWindow("lena", 10, 10)
28 waitKey()
29 
30 # save image
31 #imwrite("lena1.jpg", im)
32 
33 # color space
34 '''
35     cv2.COLOR_BGR2GRAY
36     cv2.COLOR_BGR2RGB
37     cv2.COLOR_GRAY2BGR
38 '''
39 gray = cvtColor(im, COLOR_BGR2GRAY)
40 namedWindow("lena_gray")
41 imshow("lena_gray", gray)
42 waitKey()
43 
44 destroyAllWindows()