Displaying zed camera output

Display zed camera image (from left camera) and depth map in real time.

from fish_hawk import ZedNode, pause
from time import time
import cv2

update_period = 0.05
runzed = ZedNode()
try:
    print("starting up communication with Zed camera")
    runzed.isactive(True)
    runzed.print_camera_information()
    while True:
        loop_start = time()
        isnew = runzed.check_readings()
        if isnew:
            cv2.imshow("image", runzed.image)
            cv2.imshow("depth", runzed.depth)
        # sleep to maintain constant rate
        pause(loop_start, update_period)
finally:
    print("Shutting down communication with Zed camera")
    cv2.destroyAllWindows()
    runzed.isactive(False)