Rotating Images

import cv2
import numpy as np

image = cv2.imread("photo.jpg")
h, w = image.shape[:2]

# METHOD 1: Simple 90/180/270 degree rotations
# Fastest — no interpolation needed
rot_90  = cv2.rotate(image, cv2.ROTATE_90_CLOCKWISE)
rot_180 = cv2.rotate(image, cv2.ROTATE_180)
rot_270 = cv2.rotate(image, cv2.ROTATE_90_COUNTERCLOCKWISE)

# METHOD 2: Arbitrary angle rotation with warpAffine
def rotate_image(image, angle_degrees):
    """Rotate image by any angle around its centre."""
    h, w = image.shape[:2]
    centre = (w // 2, h // 2)

    # Get the rotation matrix
    M = cv2.getRotationMatrix2D(centre, angle_degrees, scale=1.0)

    # Apply the rotation
    rotated = cv2.warpAffine(image, M, (w, h))
    return rotated

rot_45  = rotate_image(image, 45)
rot_30  = rotate_image(image, 30)
rot_neg15 = rotate_image(image, -15)  # Negative = counter-clockwise

cv2.imwrite("rotated_90.jpg", rot_90)
cv2.imwrite("rotated_45.jpg", rot_45)
print("Rotation complete")