AccumulateBackground.py

"""
Run once to accumulate background of a video, i.e. an image with non-moving objects is generated. Every moving object will vanish.
Uncomment imwrite command in Line 53 to save background as backg.jpg
"""

import numpy as np
import cv2
import os
from PIL import Image


dir = 'C:\\Users\\xyz\\Videos'
os.chdir(dir)

fname = 'video.avi'

cap = cv2.VideoCapture(fname)

_, firstframe = cap.read()
gray = cv2.cvtColor(firstframe, cv2.COLOR_BGR2GRAY)
avg = np.float64(gray)


cv2.namedWindow('backg', cv2.WINDOW_NORMAL)


while True:
    grabbed, frame = cap.read()
    key = cv2.waitKey(1) & 0xFF
    
    frame_nr = cap.get(cv2.CAP_PROP_POS_FRAMES)
    print frame_nr
    
    if not grabbed:
        print "Processing " + fname + " ended"
        break
    img_gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY).astype('float64')  
    cv2.accumulate(img_gray,avg)
        

    backg = avg/frame_nr
  
    cv2.imshow('backg',backg.astype('uint8'))
    im = Image.fromarray(backg)
    filename = 'background%i.tif' %frame_nr
    im.save(filename)


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


#cv2.imwrite('backg.jpg',backg)
cv2.destroyAllWindows()