LADDER is a hierarchical symbolic shape based sketching language to describe how sketched diagrams in a domain are drawn, displayed and edited. This domain description is then automatically translated into shape recognizers, editing recognizers and shape exhibitors for use with the customizable base domain independent creating a domain specific sketch interface thet recognizes the shapes in the domain, displaying them and allowing them to edited as specified in the decsription
LADDER descriptions primarily concern shape, stroke order and direction. LADDER consists of predefined shapes, constraints, Editing behaviors and display methods as well as syntax for specifying domain description.
Both top-down and bottom-up recognition is used for sketch recognition using LADDER.
two types of constraints are used - hard and soft. Hard constraints must be satisfied. Soft can aid recognition by specifying relationships that usually occur.
Shape definition: Definition of shape consists of following: Components, constraints, aliases, editing, display. The shapes can be defined hierarchically. Also, it is possible to define abstract shapes.
The language consists of predefined shapes, constraints, editing and display methods.
Steps in recognition
Primitive recognition: This is domain independent and can produce more than one interpretation. All interpretations are sent to higher level recognizer
Domain shape recognizer: It is performed by Jess rule based system.
The system was evaluated by using it for multiple domains: UML class diagram, mechanical engineering, COA, flow charts.
My thoughts: This is a very important progress in sketch recognition. The exponential time here can be avoided here using the technique used in paper "Recognizing Interspersed Sketched Quickly" where the sub trees are pruned.
LADDER descriptions primarily concern shape, stroke order and direction. LADDER consists of predefined shapes, constraints, Editing behaviors and display methods as well as syntax for specifying domain description.
Both top-down and bottom-up recognition is used for sketch recognition using LADDER.
two types of constraints are used - hard and soft. Hard constraints must be satisfied. Soft can aid recognition by specifying relationships that usually occur.
Shape definition: Definition of shape consists of following: Components, constraints, aliases, editing, display. The shapes can be defined hierarchically. Also, it is possible to define abstract shapes.
The language consists of predefined shapes, constraints, editing and display methods.
Steps in recognition
Primitive recognition: This is domain independent and can produce more than one interpretation. All interpretations are sent to higher level recognizer
Domain shape recognizer: It is performed by Jess rule based system.
The system was evaluated by using it for multiple domains: UML class diagram, mechanical engineering, COA, flow charts.
My thoughts: This is a very important progress in sketch recognition. The exponential time here can be avoided here using the technique used in paper "Recognizing Interspersed Sketched Quickly" where the sub trees are pruned.
I like your summary; it seems to capture most of the important ideas about LADDER. I also like that you reviewed this paper after the one on interspersed sketch recognition. It was a good idea to tie them together in the discussion since it shows more about the connection among some of Dr. Hammond's work.
ReplyDeleteNice concise summary. You have written key points in very less space. Avoiding verbosity is always great for blog readers.
ReplyDelete