Generated image from numpy array

gen_image.py

import cv2
import numpy as np
import time 
from timeit import default_timer as timer

HEIGHT=480
WIDTH=640

FONT=cv2.FONT_HERSHEY_SIMPLEX
bottomLeftCornerOfText = (100,100)
FONT_SCALE=2
fontColor              = (0,255,0)
lineType               = 2
start = timer()

while True:
    frame = np.zeros((HEIGHT, WIDTH,3), np.uint8)
    end = timer()
    delta_sec = round(end-start, 2)
    cv2.putText(frame,str(delta_sec), 
    bottomLeftCornerOfText, 
    FONT, 
    FONT_SCALE,
    fontColor,
    lineType)
    cv2.imshow("win", frame)

    if cv2.waitKey(1) & 0xFF == ord('q'): 
        break
    time.sleep(1/30)