Extract background (in grayscale) from video if the camera is not moving...

background_extraction.py

import cv2
import numpy as np

from skvideo.io import vreader

VIDEO_PATH = "room.mp4" #my room where i'm moving and i want to remove myself to get only the background...

cap = vreader(VIDEO_PATH)
L = list(cap)
L = map(lambda img: cv2.cvtColor(img, cv2.COLOR_BGR2GRAY), L) #to gray scale
cv2.imshow("1st frame : ", L[0])

L = np.array(L)

#out will be the background image...
out = L[0]

#this can take a while... (depend of the size of frame & # fo frames)
for i in range(len(L[0])):
    for j in range(len(L[0][0])):
        out[i,j] = np.median(L[:,i,j]) #sorted(L[:,i,j])[len(L) // 2]

cv2.imshow("background", out) #this is the background... :D

cv2.imwrite("bg.png", out) #save the background as gray scale