In this tutorial, we will use an example to show you how to detect and correct the text skew using python opencv. you can learn how to do step by step.

1.Read an image with text

import cv2
import numpy as np

img = cv2.imread("pytext1.png")

2.Convert the image into a grayscale image

gray_img=cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

3.Invert the grayscale image

gray_img=cv2.bitwise_not(gray_img)

4.Select the x and y coordinates of the pixels greater than zero

coordinates = np.column_stack(np.where(gray_img > 0))

5.Calculate the skew angle

ang=cv2.minAreaRect(coordinates)[-1]
if ang<-45:
    ang=-(90+ang)
else:
    ang=-ang

6.Calculate the center of the text region

height, width = img.shape[:2]
center_img = (width / 2, height / 2)

7.Get the rotation matrix

rotationMatrix = cv2.getRotationMatrix2D(center, angle, 1.0)
rotated_img = cv2.warpAffine(img, rotationMatrix, (width, height), borderMode = cv2.BORDER_REFLECT)

8.Display the rotated image

cv2.imshow("Rotated Image", rotated_img)
cv2.waitKey(0)

Then, we will get the correct text skew.