script.py

import cv2
import numpy as np


def get_frame_averages(video_path):
    vc = cv2.VideoCapture(video)

    if vc.isOpened():
        rval, frame = vc.read()
    else:
        rval = False

    frames = []


    while rval:
        rval, frame = vc.read()
        frame = np.reshape(frame, (-1, frame.shape[2]))
        av = np.average(frame, axis=0)
        frames.append(av)

    vc.release()

    return np.array(frames)


def squish_averages(averages, n):
    new_image = []
    frame_per_bucket = len(averages) / width or 1
    for frames in np.split(averages, range(frame_per_bucket, len(averages), frame_per_bucket)):
        av = np.average(frames, axis=0)
        new_image.append(av)
    return np.array(new_image)

video = 'test.mp4' # input video
imagePath = 'test.png' # output image
height = 1080 # height of output image
width = 1920 # width of output image

frames = get_frame_averages(video)
image = squish_averages(frames, width)
n, d = image.shape
image = np.repeat(image, height, axis=0)
image = np.reshape(image, (n, height, d))
cv2.imwrite(imagePath, image.transpose((1, 0, 2)))