Draw horizontal epipolar lines - rectification check

epipolar_lines.py

import sys
import cv2
import numpy as np
if len(sys.argv) < 3:
    raise RuntimeError('Please provide left and right image files as params')
print('Use left-click, `w` and `s` to move line drawn')

img1 = cv2.imread(sys.argv[1])
img2 = cv2.imread(sys.argv[2])
stacked = np.concatenate((img1, img2), axis=1)

def draw_line(img, row, color):
    cv2.line(img, (0, row), (img.shape[1], row), color, 1)
    
if 1:  # Draw epipolar lines every N rows
    line_row = 0
    while line_row < stacked.shape[0]:
        draw_line(stacked, line_row, (255, 0, 0))
        line_row += 30

fname = 'out.png'
cv2.imwrite(fname, stacked)
print('Stacked frame saved to:', fname)

current_row = -1
window = 'stacked'
cv2.namedWindow(window)
cv2.imshow(window, stacked)

def click(event, x, y, flags, param):
    if event == cv2.EVENT_LBUTTONDOWN:
        # print('Clicked:', x, y)
        global current_row
        current_row = y
cv2.setMouseCallback(window, click)

prev_row = current_row
while True:
    if prev_row != current_row:
        # print('Draw on line:', current_row)
        prev_row = current_row
        img = stacked.copy()
        draw_line(img, current_row, (0, 255, 0))
        cv2.imshow(window, img)

    key = cv2.waitKey(10)
    if key == ord('q'):
        break
    elif key == ord('w'):
        current_row -= 1
    elif key == ord('s'):
        current_row += 1