METHOD AND APPARATUS FOR FORMAT CONVERSION OF A HIERARCHICALLY STRUCTURED PAGE DESCRIPTION LANGUAGE DOCUMENT

A method and apparatus for conversion of a document from one format to another format. The invention inputs a binary file and determines the cleartext name for each ASN.1 tag in the binary file. An element table is used to store the features of each element and the sub-elements which are permitted to appear under each element are stored in sub-element linked list data structures referred to by the element table. It is possible for the binary encoding to be in an indefinite or definite length format and an element stack is used to keep track of the length of the binary file. The element stack is also used to keep track of the elements which are being processed in the hierarchy of the document. After a binary element is converted, the information pertaining to the cleartext representation of the binary element is stored in a double linked list data structure which refers to a previous element and a next element. After the entire file has been converted, the information stored in the double linked list data structure is written to an output file.