Python/digital_image_processing/rotation/rotation.py
Matheus T. Guimarães 5fd868c460 Add algorithm to rotate images (#1420)
* Add algorithm to rotate image

* Edit function to be compliant in Black and Flake8 formats

* Add type hints in get_rotation() and  enumerate() in loop
2019-10-22 21:19:38 +02:00

53 lines
1.6 KiB
Python

from matplotlib import pyplot as plt
import numpy as np
import cv2
def get_rotation(
img: np.array, pt1: np.float32, pt2: np.float32, rows: int, cols: int
) -> np.array:
"""
Get image rotation
:param img: np.array
:param pt1: 3x2 list
:param pt2: 3x2 list
:param rows: columns image shape
:param cols: rows image shape
:return: np.array
"""
matrix = cv2.getAffineTransform(pt1, pt2)
return cv2.warpAffine(img, matrix, (rows, cols))
if __name__ == "__main__":
# read original image
image = cv2.imread("lena.jpg")
# turn image in gray scale value
gray_img = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
# get image shape
img_rows, img_cols = gray_img.shape
# set different points to rotate image
pts1 = np.float32([[50, 50], [200, 50], [50, 200]])
pts2 = np.float32([[10, 100], [200, 50], [100, 250]])
pts3 = np.float32([[50, 50], [150, 50], [120, 200]])
pts4 = np.float32([[10, 100], [80, 50], [180, 250]])
# add all rotated images in a list
images = [
gray_img,
get_rotation(gray_img, pts1, pts2, img_rows, img_cols),
get_rotation(gray_img, pts2, pts3, img_rows, img_cols),
get_rotation(gray_img, pts2, pts4, img_rows, img_cols),
]
# plot different image rotations
fig = plt.figure(1)
titles = ["Original", "Rotation 1", "Rotation 2", "Rotation 3"]
for i, image in enumerate(images):
plt.subplot(2, 2, i + 1), plt.imshow(image, "gray")
plt.title(titles[i])
plt.axis("off")
plt.subplots_adjust(left=0.0, bottom=0.05, right=1.0, top=0.95)
plt.show()