1. An electronic method for image de-noising, the method comprising: receiving image data comprising a NIR image and a visible light image; aligning pixels in the NIR image with corresponding pixels in the visible light image; determining gradient vectors in the NIR image and gradient vectors in the visible light image; generating a gradient scale map from the gradient vectors in the NIR image and the gradient vectors in the visible light image; and using the gradient scale map to de-noise the visible light image.