Building Computer Vision Projects with OpenCV 4 and C++

Generating an evil mode using edge filters

Cartoons and comics always have both good and bad characters. With the right combination of edge filters, a scary image can be generated from the most innocent looking people! The trick is to use a small edge filter that will find many edges all over the image, then merge the edges using a small median filter.

We will perform this on a grayscale image with some noise reduction, so the preceding code for converting the original image to grayscale and applying a 7 x 7 median filter should still be used (the first image in the following diagram shows the output of the grayscale median blur). Instead of following it with a Laplacian filter and Binary threshold, we can get a scarier look if we apply a ...