Set Camera Timer Using OpenCV-Python

Most of you must have clicked the photograph with a Timer. This feature sets a countdown before clicking a photograph. In this tutorial, we will be doing the same i.e. creating our own camera timer using OpenCV-Python. Sounds interesting, so let’s get started.

The main idea is that whenever a particular key is pressed (Here, I have used ‘q’), the countdown will begin and a photo will be clicked and saved at the desired location. Otherwise the video will continue streaming.

Here, we will be using cv2.putText() function for drawing the countdown on the video. This function has the following arguments

cv2.putText(img, text, position, font, fontScale, color, thickness, lineType, bottomLeftOrigin)

This function draws the text on the input image at the specified position. If the specified font is unable to render any character, it is replaced by a question mark.

Now let’s see how to do this

Steps:

• Open the camera using cv2.VideoCapture()
• Until the camera is open
  • Read the frame and display it using cv2.imshow()
  • Set the countdown. Here, I have taken this as 30 and I am displaying it after 10 frames so that it is easily visible. Otherwise, it will be too fast. You can set it to anything as you wish
  • Set a key for the countdown to begin
  • If the key is pressed, show the countdown on the video using cv2.putText(). As the countdown finishes, save the frame at the desired location.
  • Otherwise, the video will continue streaming
• On pressing ‘Esc’ the video will stop streaming.

Code:

import cv2
import time
 
# Open the camera
cap = cv2.VideoCapture(0)
 
while True:
    # Read and display each frame
    ret, img = cap.read()
    cv2.imshow('a',img)
    k = cv2.waitKey(125)
    # Specify the countdown
    j = 30
    # set the key for the countdown to begin
    if k == ord('q'):
        while j>=10:
            ret, img = cap.read()
            # Display the countdown after 10 frames so that it is easily visible otherwise,
            # it will be fast. You can set it to anything or remove this condition and put 
            # countdown on each frame
            if j%10 == 0:
                # specify the font and draw the countdown using puttext
                font = cv2.FONT_HERSHEY_SIMPLEX
                cv2.putText(img,str(j//10),(250,250), font, 7,(255,255,255),10,cv2.LINE_AA)
            cv2.imshow('a',img)
            cv2.waitKey(125)
            j = j-1
        else:
            ret, img = cap.read()
            # Display the clicked frame for 1 sec.
            # You can increase time in waitKey also
            cv2.imshow('a',img)
            cv2.waitKey(1000)
            # Save the frame
            cv2.imwrite('D:/downloads/camera.jpg',img)
    # Press Esc to exit
    elif k == 27:
        break
cap.release()
cv2.destroyAllWindows()

The output looks like this

Hope you enjoy reading.

If you have any doubt/suggestion please feel free to ask and I will do my best to help or improve myself. Good-bye until next time.