Gaussian filtering

OpenCV provides the cv2.GaussianBlur() function, which blurs an image by using a Gaussian kernel. This kernel can be controlled using the following parameters: ksize (kernel size), sigmaX (standard deviation in the x-direction of the Gaussian kernel), and sigmaY (standard deviation in the y-direction of the Gaussian kernel). In order to know which kernel has been applied, you can make use of the cv2.getGaussianKernel() function.

For example, in the following line of code, cv2.GaussianBlur() blurs the image using a Gaussian kernel of size (9, 9):

smooth_image_gb = cv2.GaussianBlur(image, (9, 9), 0)