PADEL - A Pattern Description Language.
Abstract
A large class of optical pattern recognition problems may be described in terms of line drawings. Such line drawings are particularly amenable to the composition of strings of descriptors which may be processed in many ways to produce picture rotations, reflections and others as well as to extract pattern features. The paper describes line drawings in symbol strings. The language is a tranformational grammar in which elements of the line drawing, or picture, correspond to elements in the description. The correspondence is reversible so that given a grammatically correct string in PADEL a line drawing may be constructed. Using the language, several topological transformations are described in which the picture is modified by simple manipulation of the strings. First the simple tranformations of rotations, reflections, and scale changes are described. Then a non uniform, one dimensional scale changes is described in which the pictures scale is changed along one axis only. This may be termed 'rubber sheet warping'. Finally the process of identifying pattern features is described. It is then shown how PADEL may be applied to the recognition of fixed oriented line drawings. Thus, the language is shown to be very useful in recogniaing hand printed alpha numeric characters. Examples of this recognition process are given. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1970
- Accession Number
- AD0714594
Entities
People
- Kenneth J. Breeding
Organizations
- Ohio State University