Copyright (C) 1996, 1997 Aladdin Enterprises. All rights reserved. This file is part of Aladdin Ghostscript. Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND. No author or distributor accepts any responsibility for the consequences of using it, or for whether it serves any particular purpose or works at all, unless he or she says so in writing. Refer to the Aladdin Ghostscript Free Public License (the "License") for full details. Every copy of Aladdin Ghostscript must include a copy of the License, normally in a plain ASCII text file named PUBLIC. The License grants you the right to copy, modify and redistribute Aladdin Ghostscript, but only under certain conditions described in the License. Among other things, the License requires that the copyright notice and this notice be preserved on all copies. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - This file, ps2pdf.txt, contains some information about Ghostscript's PostScript to PDF converter. For an overview of Ghostscript and a list of the documentation files, see README. About ps2pdf ============ ps2pdf is a work-alike for a large subset of Adobe's Acrobat Distiller (TM) product: it converts PostScript files to PDF files. ps2pdf is implemented as a very small shell script (batch file) that invokes Ghostscript selecting a special "output device" called pdfwrite. In order to use ps2pdf, you must have included the pdfwrite device in the DEVICE_DEVS list at the time Ghostscript was built. Currently, this device is included in the makefiles for all 32- and 64-bit platforms. The usage for ps2pdf is: ps2pdf input.ps output.pdf or, on Unix systems and some versions of Windows NT and OS/2 only, ps2pdf input.ps which is equivalent to ps2pdf input.ps input.pdf The ps2pdf script assumes that the Ghostscript executable is named gs. On MS-DOS and MS Windows, you will need to edit the script (ps2pdf.bat) if the MS-DOS executable is named gs386: look for the line that says set PS2PDFGS=gs and change it to set PS2PDFGS=gs386 Note that to run ps2pdf on MS Windows, you need the MS-DOS executable: the Windows Program Manager's 'run' command doesn't allow you to run .bat files. Alternatively, you can run the "console mode" Windows executable by changing the above line to set PS2PDFGS=gswin32c Limitations =========== The most serious limitation of ps2pdf is that text in any font other than the 14 Adobe base fonts (Courier, Times, and Helvetica families, Symbol, and Zapf Dingbats) is converted to bitmaps. ps2pdf also usually converts strings to bitmaps if the string is in one of the 14 base fonts but it contains a character that uses a non-standard encoding. ps2pdf currently does not implement any of the image resampling or compression options of Distiller. It does implement setdistillerparams, and recognizes all of the parameters documented in Adobe Technical Note #5151 except for the ImageDict parameters, but the only ones that actually have any effect are ASCII85EncodePages, CompressPages, CompatibilityLevel, and UseFlateCompression. It could implement LZWEncode, but doesn't do so because of Unisys' threats regarding the Welch patent: instead, it treats LZWEncode as calling for Flate compression. Known problems ============== In some cases, PDF files created using ps2pdf work with Adobe Acrobat on Unix but fail using the Windows version of Acrobat. One error that has been observed using versions of Acrobat reader for Windows is: "There was an error processing a page. A rasterizer error occurred." This error has been observed using both Acrobat version 2.1 and the Alpha 2 release of Adobe Amber. (Adobe may have fixed this problem by now.) Benefits of using ps2pdf ======================== Despite the limitations of ps2pdf, the class of "suitable" documents is a large one. Many users report that the combination of of ps2pdf with Acrobat is be superior to using a generic PostScript viewer (psview or ghostview), particularly for documents with many pages where the navigational support in PDF files reduces the overhead involved in navigating conventional PostScript documents. For certain documents, ps2pdf is much faster than Adobe Distiller, and may be suitable for run-time conversions. [Note from George White: I haven't seen a head to head comparison, but distiller seems slower when running on what should be a faster system (e.g., distiller on a PPC Mac vs a 25 mhz '040 NeXT running ps2pdf), so I think this is fair -- also, one of Mark Doyle's postings indicated that distiller was not fast enough for use as a run-time server. In contrast, I find that I can use ps2pdf as a post-processor during routine document creation.] Acknowledgements ================ Thanks to George N. White III of the Ocean Sciences Division of the Bedford Institute of Oceanography in Dartmouth, Nova Scotia , for extensive testing of early versions of ps2pdf, and for contributing most of this writeup.