Ghostscript - can we substitute to ignore embedded fonts in PS?

Question

I am trying to convert a Postscript file to PDF. The PS file has an embedded font that I want to ignore and substitute with a local system font. This is because the font is OCR based and it makes more sense to read the character strings in this case.

I set up a Fontmap file but it only works when I delete the font data from the PS file, so that the font is actually missing. Is there a way to do this without modifying the PS file?

Answer 1

There is no switch or command to do this for the very good reason that it would break conformance with the specification. If you embed a font in a PostScript program that font will be used in preference to any other font.

This allows you (for example) to use specific versions of a font by embedding them, rather than relying on the font present in the interpreter which may be different.

However, because PostScript is a programming language, you could redefine the 'definefont' operator so that it examined the dictionary operand for the FontName, before defining the font, and if it is the font you want to ignore you could fail to define it. You would then go through the missing font machinery which would find your substitute.