Recognizing Free-form Hand-sketched Constraint Network Diagrams by Combining Geometry and Context

Comments

Summary

In this paper the author discusses the modeling problem of constraint satisfaction problems and uses LADDER framework to solve the modeling problem. The author develops a hand recognition technology that can recognize hand drawn representations of problems, and automatically generate constraint satisfaction models of them.

The system uses a geometric-based recognizer to allow freeform drawing. Users require no training than would be necessary to sketch on a piece of paper. The system recognizes free-form constraint network diagrams that consist of labeled nodes, labeled links and domain information about the allowable range of the variables.

Nodes are recognized as ellipses that contain variable names inside them. Undirected links are recognized as a line between two notes. Directed links are recognized as arrow that extends between two nodes. A set of rules of geometric properties are defined for variable recognition inside LADDER.

The author uses a perception based threshold to counter noise in the input. Also the author uses a length-based threshold to some what relieve the problems where perception based threshold run into problems.

The system also supports editing in the form of deletion of shapes, movement of shapes, rubber-band of links and scaling of nodes.

Discussion

Yet another implementation using the LADDER framework. This simply demonstrates the capabilities of the framework and possibilities of its use.

The paper does not demonstrate any new or innovative features.