import cv2
image_path= #put your image path here
#use imread() function to read image data to variable img.
img = cv2.imread(image_path)
#display image data in a new window with title 'I am an image display window'
cv2.imshow('I am an image display window',img)
#wait until user hits any key on keyboard
cv2.waitKey(0)
#close any windows opened by opencv
cv2.destroyAllWindows()
To control the size of the display window on the screen, add the following commands before the cv2.imshow command:
window_width=800 #size of the display window on the screen
window_height=600
#open an empty window with a title.
#The flag cv2.WINDOW_NORMAL allows the window to be scaleable.
cv2.namedWindow('I am an image display window', cv2.WINDOW_NORMAL)
#scale the image display window to desired size
cv2.resizeWindow('I am an image display window', window_width, window_height)
see openCV docs for further details