CODEWITHSUNDEEP
pythonopencvcomputer-vision
mk56852
mk56852

Reputation: 17

How to undo the rotation of an image?

Here is an example of an image. The object in the image seems to be rotated. How do I undo the rotation of it?

enter image description here

Upvotes: 0

Views: 430

Answers (2)

Abdelsalam Hamdi
Abdelsalam Hamdi

Reputation: 515

You can get the contours in the image than convert them to a rotate rect using opencv. the rotate rect will provide you the angle. all you need to do than is to rotate the image using that angle. The code is attached below

import cv2
import numpy as np
img = cv2.imread("opencv_task.png",0)
con , _ = cv2.findContours(img,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
minRect = cv2.minAreaRect(con[0])

## uncomment these if you want to draw a rectangle
# box = cv2.boxPoints(minRect)
# box = np.intp(box) #np.intp: Integer used for indexing (same as C ssize_t; normally either int32 or int64)
# cv2.drawContours(img, [box], 0, (255,255,0))

(h, w) = img.shape[:2]
(cX, cY) = (w // 2, h // 2)

#minRect[2] is the angle of the rotate rectangle
# rotate our image by minRect[2] degrees around the center of the image

M = cv2.getRotationMatrix2D((cX, cY), minRect[2], 1.0)
rotated = cv2.warpAffine(img, M, (w, h))
cv2.imshow("Rotated", rotated)
cv2.waitKey(0)
cv2.destroyAllWindows()

the output sample is attached here enter image description here

Upvotes: 5

Joaquin Hoffmann
Joaquin Hoffmann

Reputation: 528

In the image library from PIL there is a rotate method. Here goes an example of function that could help you

from PIL import Image

def rotar(a,t): #a es el nombre de la imagen, t son los grados en deg
    colorImage  = Image.open(a)
    rotated     = colorImage.rotate(t, expand=True)
    rotated.save('rotated.png')

Upvotes: 0

Related Questions