The last section of this chapter is dedicated to creating another effect, called cartoonize; the purpose of this effect is to create an image that looks like a cartoon. To do this, we divide the algorithm into two steps: edge detection and color filtering.
The cartoonCallback function defines this effect, which has the following code:
void cartoonCallback(int state, void* userData)
{
/** EDGES **/
// Apply median filter to remove possible noise
Mat imgMedian;
medianBlur(img, imgMedian, 7);
// Detect edges with canny
Mat imgCanny;
Canny(imgMedian, imgCanny, 50, 150);
// Dilate the edges
Mat kernel= getStructuringElement(MORPH_RECT, Size(2,2));
dilate(imgCanny, imgCanny, kernel);
// Scale edges values to 1 and invert values
imgCanny= imgCanny/255;
imgCanny= 1-imgCanny;
// Use float values to allow multiply between 0 and 1
Mat imgCannyf;
imgCanny.convertTo(imgCannyf, CV_32FC3); ...