AttributeError: module 'cv2' has no attribute 'SSIM'

This error occurs when you try to use the SSIM (Structural Similarity Index) function of the cv2 module in Python, but it's not available in your version of OpenCV.

To fix this error, you can try upgrading your OpenCV version to the latest one by running the following command in your terminal:

!pip install opencv-python-headless

Alternatively, you can use the scikit-image library to calculate SSIM instead of cv2. You can install it by running the following command:

!pip install scikit-image

And then you can use the following code to calculate SSIM:

from skimage.measure import compare_ssim
import cv2

img1 = cv2.imread('image1.jpg')
img2 = cv2.imread('image2.jpg')

score, diff = compare_ssim(img1, img2, full=True, multichannel=True)
print('SSIM:', score)