Prerequisites: OpenCV Python Tutorial
OpenCV (Open Source Computer Vision) is a computer vision library that contains various functions to perform operations on pictures or videos. This library is cross-platform that is it is available on multiple programming languages such as Python, C++, etc.
Green Screen removal is used in the VFX industry for changing the scenes. Here, we will use OpenCV – Python to do the same.
Approach:
- Import all necessary libraries
- Load the images or videos
- Resize the images and the videos to the same size
- Load the upper and lower BGR values of the green color
- Apply the mask and then use bitwise_and
- Subtract bitwise_and from the original green screen image
- Check for matrix value 0 after subtraction and replace it by the second image
- You get the desired results.
Below is the implementation.
Python3
import cv2
import numpy as np
video = cv2.VideoCapture( "green.mp4" )
image = cv2.imread( "bg.jpeg" )
while True :
ret, frame = video.read()
frame = cv2.resize(frame, ( 640 , 480 ))
image = cv2.resize(image, ( 640 , 480 ))
u_green = np.array([ 104 , 153 , 70 ])
l_green = np.array([ 30 , 30 , 0 ])
mask = cv2.inRange(frame, l_green, u_green)
res = cv2.bitwise_and(frame, frame, mask = mask)
f = frame - res
f = np.where(f = = 0 , image, f)
cv2.imshow( "video" , frame)
cv2.imshow( "mask" , f)
if cv2.waitKey( 25 ) = = 27 :
break video.release() cv2.destroyAllWindows() |
Output: