Java：将PostScript文件转换为文本

Question

Is there a Java Library that converts a PostScrpit File ".ps" into a String or TextFile (or something I can read with an InputStream)?

I have these Files and need to read them and handle them accourding to the Text in it. They allway contain only Text and usually its just one line like

date:SWYgeW91IHJlYWQgdGhpcyB5b3UncmUgcHJvYmFibGUgdG8gY3VyaW91cyAgYnV0IG5pY2UgdHJ5IGFueXdheS4gUGxlYXNlIEhlbHA=

in it.

Right now I convert it into a PDF and "read" it with an OCR Engine. But it seems a litte bit over the top for just one line.

Is there an other way to do it?

If you could point me in the right direction, that would be great.

Answer 1

PostScript is a language to define graphical output on paper, to a printer device. As such it does not really contain plaintext, and "extracting" text from it poses problems. It could for instance be programmatically determined in places, or it could be interspersed with PS code making the text data useless.

Normally you would output a modified PS to a printer (real or virtual) with a specific config that leads the result to be output as a standard text sequence (without the graphical formatting).

This is often done by altering the PS code file, to alter the text output command.

A desciption of this method can be found in part 3 of following Waikato Uni PM

http://www.cs.waikato.ac.nz/~ihw/papers/98NM-Reed-IHW-Extract-Text.pdf

Answer 2

If you convert the PostScript file to PDF (for example, with Ghostscript ps2pdf or with Acrobat Distiller), you could then read this file using iText ( http://itextpdf.com ). You could also convert the PDF into a more readable form using RUPS, one of the iText tools.