Scribble Path Smoothing

Some devices don’t report precise touch point readings. This results in noisy(i.e., not smooth) scribble paths. We need to clean up the scribble data.

Firstly, we use the Douglas-Peucker path simplification algorithm to reduce the number of points in a scribble. Douglas-Peucker is able to remove about 80% of points while retaining shape of scribble. It works by removing any points that fall near a line between some other two points. Then when drawing a path with the reduced set of points, a shape very similar to the original scribble path is reproduced. Read more…