CODEWITHSUNDEEP
opencvvideocomputer-visionvideo-processingvideo-capture
pantelis
pantelis

Reputation: 23

How to convert a rgb video to grayscale and save it?

im new to python and i want to turn a color video to grayscale and then save it. Ive tried this code to make it grayscale but i cant save it. Any ideas?

import cv2

source = cv2.VideoCapture('video.mp4')
while True:
    ret, img = source.read()

gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

cv2.imshow('Live', gray)

key = cv2.waitKey(1)
if key == ord('q'):
    break

cv2.destroyAllWindows()
source.release()

Upvotes: 1

Views: 5309

Answers (2)

FirefoxMetzger
FirefoxMetzger

Reputation: 3260

Here is a shorter way of doing this using ImageIO. The example use one of our standard images, so you can run it locally, too.

import imageio.v3 as iio

with iio.imopen("output_video.mp4", "w") as file:
    file.init_video_stream("libx264", fps=24, pixel_format="gray")
    for frame in iio.imread("imageio:cockatoo.mp4"):
        file.write_frame(frame)

Note that you will have to install its pyav backend (pip install imageio[pyav]) for this to work.

Upvotes: 1

user14554230
user14554230

Reputation:

This is the way how to write an RGB video file into the grayscale video

# importing the module 
import cv2 
import numpy as np
  
# reading the vedio 
source = cv2.VideoCapture('input.avi') 

# We need to set resolutions. 
# so, convert them from float to integer. 
frame_width = int(source.get(3)) 
frame_height = int(source.get(4)) 
   
size = (frame_width, frame_height) 

result = cv2.VideoWriter('gray.avi',  
            cv2.VideoWriter_fourcc(*'MJPG'), 
            10, size, 0) 
  
# running the loop 
while True: 
  
    # extracting the frames 
    ret, img = source.read() 
      
    # converting to gray-scale 
    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) 

    # write to gray-scale 
    result.write(gray)

    # displaying the video 
    cv2.imshow("Live", gray) 
  
    # exiting the loop 
    key = cv2.waitKey(1) 
    if key == ord("q"): 
        break
      
# closing the window 
cv2.destroyAllWindows() 
source.release()

If helpful this for you give 👍

Upvotes: 2

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