Reading #29: Scratch Input Creating Large, Inexpensive, Unpowered and Mobile Finger Input Surfaces (Harrison)

Comment Location:
https://www.blogger.com/comment.g?blogID=19209095&postID=1742929146352552782&isPopup=true

Summary:
This paper attempts to recognize sketches by the sound created when the user creates the sketch.  A stethoscope/microphone combination is placed on the drawing surface and the user creates the sketch.  The amplitude of the sound wave is mapped out and analyzed to determine the shape drawn.  For example, a rectangle typically has 4 amplitude peaks and a triangle typically has 3 amplitude peaks.

The author professed a high recognition rate of 90%, but he used some very simple shapes.  The number of shapes used was very small as well.  From what I read, the author assumed shapes were drawn in the same manner (very incorrect when sketching letters).

Discussion:
This paper introduced the idea of sound-based sketch recognition to me.  However, sound-based recognition should be used to create a portable sketch recognition system.  I want to see a "Magic Pen" that the user can use to sketch anywhere: on the bus, on the restroom wall, on the table or counter at Taco Bell.  The sound and positioning data are collected to recognize the sketch on a separate screen.

By itself, sound recognition of sketches is not very effective.  There are simply too many variations for a single shape and too few features to identify the shapes.  In addition, many of the variations of shapes overlap with each other, making distinction between shapes very difficult.  I am not the only one to say this.  There is at least one other paper on this topic that expresses similar sentiments.