PostScriptTrace: Convert PostScript file to RGML file

Description

Converts a PostScript file into an RGML file, which is an XML document describing an image that can be read into R.

Usage

PostScriptTrace(file, outfilename,
                       charpath=TRUE, setflat=NULL,
                       encoding="ISO-8859-1")

Arguments

file

The name of the PostScript file.

outfilename

The name of the XML document.

charpath

A boolean indicating whether text in the PostScript file should be converted to vector outlines, or left as just text.

setflat

A number that controls how many straight lines a curve is broken into. Lower values break a curve into more lines.

encoding

A character value giving the encoding for the resulting RGML file.

Details

This function calls ghostscript to do the conversion, so will only work if ghostscript is installed on your system.

If text is converted to outlines, it can be drawn as outlines, or filled using a crude algorithm which may or may not work (see grid.picture). On the other hand, if text is left as just text, font information is not stored so the text may not end up looking much like the original.

Ghostscript is only going to emit text in a single-byte encoding, so the RGML file should have an explicit encoding (otherwise XML parsers are likely to assume UTF-8 and barf on any non-ASCII text). The default encoding used is ISO-8859-1 (ISOLatin1), but you can specify another if you know that the source file has text that ghostscript will emit in a different encoding. There may have to be a bit of guesswork, or inspection of the source PostScript file.

References

http://www.cs.wisc.edu/~ghost/