Sketch Recognition for Computer-Aided Design

Author: Christopher Herot

Comments:

Summary:

This paper discusses about enhancing user experience in Sketch recognition system. This is done by understanding user intent from speed, pressure and sequence of the stroke. This paper highlights the cumbersome nature of the explicit action - response systems and proposes modifications which would alleviate this overhead.

First phase of interpretation - The sketch is converted to line and curves. Lines, curves and corners are identified using patterns in speed. Curves are smoothened using Bspline curve fit. The system assumes that strokes drawn slowly are intended more literally than those drawn hastily. The output is then processed for overtracing and thickness. Thickness may be used as a measure of the degree of emphasis intended for the line.

Second phase of interpretation - The next phase is latching the corners of the stroke which do not actually interesect. The latching radius is determined using the speed, line length and density of line around each point.

Further interpretations are done based on the context.

In order to tune the system to particular user sketching style, the system is trained with practise patterns drawn by the user.

This system with the help of above interpretations can decrease the number of interactions with the user compared to the traditional action - response system. Allowing multi level viewing and manipulation of the interpreted data is also important. This allows user to edit raw data as well as the interpreted data. The system adapts to the interpretation errors by changing the parameters as they are corrected by the user.

The paper also emphasises on the inclusion of the user's model of the system in the system model. This would imply tracking the user confidence in the system. This would heklp the system provide the right level of feedback and degree of inference making. This part is very critical since this is related to user behavior.

Discussion:

Understanding user intent using the speed, pressure and sequence seems to be very interesting idea. This seems to be practical but the final part of the paper which proposes a system which includes user's model of the system seems to be complex and theoretical. Parameters to capture user confidence is not clear.