Software validation method and system

Abstract

A method embodiment of the invention tests revisions made to printer graphics interpreter software. A test suite of POSTSCRIPT, PCL, or other high-level printer language is input to a production version of a printer's internal interpreter software. A first bit-map is generated by the interpreter that is normally used to control each pixel in the printing of a page. The same test suite is fed to a work-in-progress revision of the printer's internal interpreter software. A second bit-map is generated. The first and second bit-maps are subtracted from one another. A difference bit-map is inspected. If only minor shifts of objects are noted, or if no differences at all are apparent, the work-in-progress revision is accepted as the new production standard. The second bit-map is used to replace the first. Otherwise, the work-in-progress revision of the printer's internal interpreter software is reworked to correct the printing interpretation errors it was making.

Dependencies are inferred from the claim text.