Python Opencv Display Time Countdown Using Puttext In Webcam Video

Aim: I'd like to put text on each frame obtained by the webcam so that the text '3', '2', '1' can be displayed for a second each. Thus portraying a countdown timer. Following the

Solution 1:

After struggling for two days and reading up on datetime module I have what I need. I can however accept an answer other than mine if it is more pythonic.

import cv2
import sys
from datetime import datetime

# Initialize variables
camSource = -1
running = True
saveCount = 0
nSecond = 0
totalSec = 3
strSec = '321'
keyPressTime = 0.0
startTime = 0.0
timeElapsed = 0.0
startCounter = False
endCounter = False# Start the camera
camObj = cv2.VideoCapture(camSource)
ifnot camObj.isOpened():
    sys.exit('Camera did not provide frame.')

frameWidth = int(camObj.get(cv2.cv.CV_CAP_PROP_FRAME_WIDTH))
frameHeight = int(camObj.get(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT))

# Start video streamwhile running:
    readOK, frame = camObj.read()

    # Display counter on screen before saving a frameif startCounter:
        if nSecond < totalSec: 
            # draw the Nth second on each frame # till one second passes  
            cv2.putText(img = frame, 
                        text = strSec[nSecond],
                        org = (int(frameWidth/2 - 20),int(frameHeight/2)), 
                        fontFace = cv2.FONT_HERSHEY_DUPLEX, 
                        fontScale = 6, 
                        color = (255,255,255),
                        thickness = 5, 
                        lineType = cv2.CV_AA)

            timeElapsed = (datetime.now() - startTime).total_seconds()
#            print 'timeElapsed: {}'.format(timeElapsed)if timeElapsed >= 1:
                nSecond += 1#                print 'nthSec:{}'.format(nSecond)
                timeElapsed = 0
                startTime = datetime.now()

        else:
            cv2.imwrite('img' + str(saveCount) + '.jpg', frame)  
#            print 'saveTime: {}'.format(datetime.now() - keyPressTime)

            saveCount += 1
            startCounter = False
            nSecond = 1# Get user input
    keyPressed = cv2.waitKey(3)
    if keyPressed == ord('s'):
        startCounter = True
        startTime = datetime.now()
        keyPressTime = datetime.now()
#        print 'startTime: {}'.format(startTime)#        print 'keyPressTime: {}'.format(keyPressTime)elif keyPressed == ord('q'):
        # Quit the while loop
        running = False
        cv2.destroyAllWindows()

    # Show video stream in a window    
    cv2.imshow('video', frame)

camObj.release()

Solution 2:

Here is a version of my own implementation of seemless dispay of countdown timer of five seconds before a 10 seconds video output for whatever! Please let me know any questions in comments!

defdraw_text(frame, text, x, y, color=(255,0,255), thickness=4, size=3):
            if x isnotNoneand y isnotNone:
                cv2.putText(
                    frame, text, (int(x), int(y)), cv2.FONT_HERSHEY_SIMPLEX, size, color, thickness)

    import numpy as np
    import cv2
    import time
    #timeout = time.time() + 11   # 10 seconds from now
    cap = cv2.VideoCapture(0)
    init_time = time.time()
    test_timeout = init_time+6
    final_timeout = init_time+17
    counter_timeout_text = init_time+1
    counter_timeout = init_time+1
    counter = 5while(cap.isOpened()):
        ret, frame = cap.read()
        if ret==True:
            center_x = int(frame.shape[0]/2)
            center_y = int(frame.shape[0]/2)
            if (time.time() > counter_timeout_text and time.time() < test_timeout):
                draw_text(frame, str(counter), center_x, center_y)
                counter_timeout_text+=0.03333if (time.time() > counter_timeout and time.time() < test_timeout):
                counter-=1
                counter_timeout+=1
            cv2.imshow('frame', frame)
            if (cv2.waitKey(1) & 0xFF == ord('q')) or (time.time() > final_timeout):
                breakelse:
            break# Release everything if job is finished
    cap.release()
    cv2.destroyAllWindows()