Hello,

I am trying to write a script for university project which shows a possible application of Homomorphic Encryption and facing big challenges with using Concrete Numpy. In my case I am trying to subtract one image from another in np.ndarray format that are homomorphically encrypted.

My ultimate question is: “Is it possible to use Concrete-Numpy to do cv2.subtract() of 2 np.ndarrays?”

If yes, how?

If not, why? Is there a workaround?

Example code without Concrete-Numpy:

```
def image_subtract(image1:np.ndarray, image2:np.ndarray):
# Subtract image2 from image1
differenceImage = cv2.subtract(image1, image2)
return differenceImage
image1_path = "./assets/before.jpeg"
image2_path = "./assets/after.jpeg"
image1 = cv2.imread(image1_path)
image2 = cv2.imread(image2_path)
result = image_subtract(image1, image2)
cv2.imshow("Result", result)
```

Here is a workable example without Homomorphic Encryption from Concrete-Numpy, but I would want to do the subtraction on 2 images that are homomorphically encrypted.

Thank you for the reply in advance.