Air drawing is a fun side project that I have done to get used to OpenCV, Mac OSX, Qt, and to manipulate video, color spaces, thresholding, blur and real-time processing.



The principle is to draw on the image with an object of a given color, here the green post-it, and to erase with one of another color, here the blue post-it. That taught me how to manage color spaces, noise, processing time, masks and pixel access.



See also Post-it tracking