https://stackoverflow.com/questions/41995916/opencv-straighten-an-image-with-python

gistfile1.txt

import numpy as np
import cv2

#---- 4 corner points of the bounding box
pts_src = np.array([[17.0,0.0], [77.0,5.0], [0.0, 552.0],[53.0, 552.0]])

#---- 4 corner points of the black image you want to impose it on
pts_dst = np.array([[0.0,0.0],[77.0, 0.0],[ 0.0,552.0],[77.0, 552.0]])

#---- forming the black image of specific size
im_dst = np.zeros((552, 77, 3), np.uint8)

#---- Framing the homography matrix
h, status = cv2.findHomography(pts_src, pts_dst)

#---- transforming the image bound in the rectangle to straighten
im_out = cv2.warpPerspective(im, h, (im_dst.shape[1],im_dst.shape[0]))
cv2.imwrite("im_out.jpg", im_out)