Match a user drawn path to an image

Question

Does anyone know of any tutorials or sample code that could help me achieve the following in an iPhone app (other than the offical Apple developer videos).

• A user draws a path on screen
• The path is compared to an already existing path to see if it matches
• A match is determined not just by shape but also by starting and ending at the correct point

Essentially tracing a path with your finger. The drawing part isn't too bad at the moment (though pretty jagged if you move your finger fast, not too bothered about that though). The main thing is the matching what you've drawn to something else part.

Answer 1

Take a look at this:

http://depts.washington.edu/aimgroup/proj/dollar/

Paper describing method is here:

http://faculty.washington.edu/wobbrock/pubs/uist-07.1.pdf