自动刷新Ubuntu树莓派中的图像

Question

I am streaming and writing an image to a particular location in a raspberry pi. Every time a new image comes it overwrites the previous one. Now if i keep that image file open, it does not get automatically updated.I have to close and reopen it for the update to happen.Is there anyway i can automatically refresh it.

I tried implementing a python code to continuously read and show the image. But still i have to refresh the window for the image to get updated. Below is the code that i used.

img = cv2.imread("Filename",1)
cv2.imshow('image',img)
cv2.waitKey(0)
cv2.destroyAllWindows()

Please suggest any alternatives. I just need to preview the stream.

Answer 1

You could use a simple loop as you can call imshow repeatedly without destroying it.

while True: #Find something to get out of here
    img = cv2.imread("Filename",1)
    cv2.imshow('image', img)
    cv2.waitKey(1)
cv2.destroyAllWindows()

Answer 2

due to opencv documenation:

For example, waitKey(0) will display the window infinitely until any keypress (it is suitable for image display). waitKey(25) will display a frame for 25 ms, after which display will be automatically closed.

So you have to set time in milliseconds instead of 0.