OpenCV 3.x with Python By Example - Second Edition

How do we move the focus around?

We now know how to create a vignette filter that focuses on the center of the image. Let's say we want to achieve the same vignette effect, but we want to focus on a different region in the image, as shown in the following figure:

All we need to do is build a bigger Gaussian kernel, and make sure that the peak coincides with the region of interest. Following is the code to achieve this:

import cv2 import numpy as np img = cv2.imread('images/input.jpg') rows, cols = img.shape[:2] # generating vignette mask using Gaussian kernels kernel_x = cv2.getGaussianKernel(int(1.5*cols),200) kernel_y = cv2.getGaussianKernel(int(1.5*rows),200) ...