Mastering OpenCV with Practical Computer Vision Projects

Generating a color painting and a cartoon

A strong bilateral filter smoothes flat regions while keeping edges sharp, and is therefore great as an automatic cartoonifier or painting filter, except that it is extremely slow (that is, measured in seconds or even minutes rather than milliseconds!). We will therefore use some tricks to obtain a nice cartoonifier that still runs at an acceptable speed. The most important trick we can use is to perform bilateral filtering at a lower resolution. It will have a similar effect as at full resolution, but will run much faster. Let's reduce the total number of pixels by a factor of four (for example, half width and half height):

Size size = srcColor.size(); Size smallSize; smallSize.width = size.width/2; smallSize.height ...