Survey on various Classes of Picture Languages

摘要

A formal language is defined as a set of strings of an alphabet which is a non-empty set. In terms of pictures, a set of pictures are called as picture language in the field of formal languages. The study of picture languages was originally prompted by the problems of image processing and pattern recognition. The matrix grammar and tiling systems have been designed to describe the picture languages. Many problems in picture languages have been formulated from one dimensional formal language theory. A method of undecidability results for regular picture languages is used to show the undecidability of the equivalence problem in regular languages Jurgen; Friedhelm (1993). The methods of mathematical linguistics have been considered for picture generation and picture description. Generally mathematical linguistics deals with strings and not with pictures. Picture language is not recognizable and also proved that this type language is both star free and piecewise testable Rosenfeld (1970).