Gesture Recognition (Hammond)

Comment Locations:
http://martysimpossibletorememberurl.blogspot.com/2010/09/hammond-gesture-recognition-survey.html#comments

Summary:
This paper covered many basics and the beginning points for sketch recognition.  The author elaborately explained the purposes of each of the features in Rubine's and Long's feature set.  The author included discussion questions for the Rubine and Long sections (I didn't notice any questions for the Wobbrock section).  Rubine and Long used different types of feature-based linear classifiers while Wobbrock implemented a template matcher; I interpreted the template matcher to mean the program finds the closest comparison of the gesture to a pre-generated set of template gestures.

Rubine and Long were more detail oriented in their classifiers while Wobbrock generalized the data set before classification.



Discussion:
I would have preferred if the author had simply given the answers to the discussion questions in the paper.  Time is valuable to me and I would prefer to have quick and complete understanding of the concepts and move on.  I did appreciate the in-depth coverage of the techniques and comparisons between Rubine, Long, and Wobbrock.  Firmly establishing the basics is absolutely necessary when learning a new discipline.

Intuitively one would think the most effective program of the three authors mentioned would depend on the data set.

Questions:
Rubine:
1) If points at an identical location are points with the same (x,y) coordinates and a different time stamp, then deleting the 1st or 2nd point there can affect the overall accuracy of the data; this is very true for the cumulative measures, like the sum of angles between each point in the stroke.

2) Removing either the 1st or the 2nd value could affect the summation features.  Ideally, the duplicate time stamps could be fixed by adding a time unit to every subsequent point (eliminating every duplicate time stamp case one at a time while preserving the integrity of the stroke as much as possible).

3)
shape 1: d
shape 2: g
shape 3: b
shape 4: e
shape 5: a
shape 6: h
shape 7: c
shape 8: f

Long:
 1) Some of the features are devoted towards finding the size of the stroke, average angle per point, and overall curviness.  I believe Long was trying to get an overall picture of the image (size of stroke and how curvy stroke was).