Cartoonize effect

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...