如果用opencv，可以找出圖像相關的contour方向，然後把它旋轉回到垂直位置。這樣的話，圖像的方格便會回復到垂直位置來排序。

import cv2
import numpy as np
import imutils
from matplotlib import pyplot as plt

# load image 
img_org = cv2.imread( "test.jpg" )

# convert to gray
img_gray = cv2.cvtColor( img_org, cv2.COLOR_BGR2GRAY )

# remove noise
img_smooth = cv2.GaussianBlur( img_gray, (11, 11), 0 )

# thresholding
img_thres = cv2.adaptiveThreshold( img_smooth, 255, cv2.ADAPTIVE_THRESH_MEAN_C, cv2.THRESH_BINARY_INV, 15, 5 )

# find contours
contours, _ = cv2.findContours( img_thres, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE )

# find contour with maximum area
maxarea = 50
for contour in contours:
    epsilon = 0.1 * cv2.arcLength( contour, True )
    poly_approx = cv2.approxPolyDP( contour, epsilon, True )
    area = cv2.contourArea( poly_approx )
    if area > maxarea:
        maxarea = area
        contour_max = poly_approx

# draw the contour
img_contour = img_org.copy()                
cv2.drawContours( img_contour, [contour_max], 0, (255, 0, 0), 3 )

# correct contour orientation
(x, y), (w, h), angle = cv2.minAreaRect( contour_max )

rot_angle = (90 + angle) if angle < -45 else angle
print( rot_angle, "deg" )

img_correct = imutils.rotate( img_contour, rot_angle )    

# show images
plt.subplot( 2, 2, 1 )
plt.imshow( img_gray, 'gray' )
plt.xticks([]), plt.yticks([])

plt.subplot( 2, 2, 2 )
plt.imshow( img_thres, 'gray' )
plt.xticks([]), plt.yticks([])

plt.subplot( 2, 2, 3 )
plt.imshow( img_contour )
plt.xticks([]), plt.yticks([])

plt.subplot( 2, 2, 4 )
plt.imshow( img_correct )
plt.xticks([]), plt.yticks([])

plt.show()

cv2.waitKey( 0 )
cv2.destroyAllWindows()