slitscan.py

import cv2
import numpy as np
import time

# create video capture
filename = "test.mp4"
cap = cv2.VideoCapture(filename)

h = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
w = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
slit_pos = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH) / 2) - 100
slit_size = 1

cv2.namedWindow('background', cv2.WINDOW_NORMAL)
cv2.namedWindow('frame', cv2.WINDOW_NORMAL)

# create a new image
background = np.zeros((h, w * slit_size, 3), np.uint8)

slit_num = 0

while(1):
    # read the frames
    success,frame = cap.read()
    if success:
        # copy a line from the frame to the background
        background[0:h,slit_num:slit_num+slit_size] = frame[0:h,slit_pos:slit_pos+slit_size]

        # increment the slit position
        slit_num+=slit_size

        # draw a line that shows the slit
        cv2.line(frame,(slit_pos,0),(slit_pos,h),(0,0,255),2)

        # show images
        cv2.imshow('background',background)
        cv2.imshow('frame',frame)

    #if key pressed is 'Esc', exit the loop
    key = cv2.waitKey(1)
    if key == 27:
        break

# copy to the result and write to a file
result = np.zeros((h, slit_num, 3), np.uint8)
result[0:h,0:slit_num] = background[0:h,0:slit_num]
cv2.imwrite(f"{filename}.{time.time()}.jpg", result)

# clean up everything
cv2.destroyAllWindows()
cap.release()