Reading #9. PaleoSketch: Accurate Primitive Sketch Recognition and Beautification (Paulson)

Comment Location:
http://christalks624.blogspot.com/2010/09/reading-9-paleosketch.html

Summary:
This is the Paleo program being used for the 1st programming assignment.  It takes a sketch and classifies each line within the sketch into primitives.  The set of primitives used can be changed in the code.  Paleo does some nice things in the pre-processing; it removes duplicate points (done by systems with high sampling rate), normalized distance
between direction extremes (NDDE) (finds circles rather well), and direction change ratio (DCR) (finds corners very well).  Here's a summary of the testing procedures:

Line: least squares fit comparison (more complicated and additional steps, but that's the gist of it).
Polyline: locate corners and do line test for each segmented line.
Ellipse: get center (average of points), major axis, minor axis; NNDE value is high, area of shape is within a threshold
Circle: same as ellipse, except major and minor axis must be close
Etc.

Those are the important ones in the first programming assignment, so those are all I listed. 


Discussion:
This paper had everything (and a few other things) I discovered using Paleo within the first 3 hours or so.  As for the results, all I care about at the moment is if they are good enough for the homework.  Since it seems like it, I'm satisfied about that.  Now, if only there was more documentation on Paleo...