PDF's lookact differently in GS and other programs than Adobe apps 420

In a message on 15 Feb 2006 11:47:58 -0800, wrote :

I suspect that KGhostRead and KPDF are frontends for ghostscript. You could try xpdf, which is NOT a frontend for ghostscript.

PDF files are 'versioned'. There is PDF-1.0. PDF-1.1 ... PDF-1.6. Ghostscript (7.x anyway) is somewhere at 1.2 or 1.3. Adobe's products are (of course!) up to PDF-1.6. The PDF standard (like the HTML standard) allows for programs processing PDF files to render things as best they can and if you feed a PDF-1.6 to ghostscript, it will do 'its best' and will likely skip the bits it does not understand. It is also possible to go from PDF to PostScript using acroread itself (using the -toPostScript CLI option) and this might solve *some* of your problems, in that it might 'level the playing field'.

Oh, part of what is going on is various things like fonts, where ghostscript has its set of GPL fonts and Adobe has its own Type-1 fonts (not GPL!). There are differences, not always subtle. Oh, ghostscript-ghostview and acroread do things differently when displaying a document on the screen. Remember that the screen resolution is like 75dpi and printers are like 300dpi (or much better). When you go to thumbnails things get even more interesting, depending on what image format you use and what DPI setting you use on the PDF or PostScript engine. I don't know if ImageMagick or PDFLib are the *best* tools here. Have you tried GIMP? I know that GIMP has the option of specifying the DPI setting pbutted to ghostscript when you go from PostScript to an image. Yes, specifying a high DPI setting means a very large image, but once you have the 'bits' one can get creative when you shrink it to a thumbnail, in terms of clever dithering and sampling games to preserve quality.

You could get the source to Ghostscript and update it to the latest standard. Note that there aren't any 'instructions is a part of the PDF that makes it display a certain way in Adobe products'. Much of this is hidden in Adobe's products. There is nothing in the PDF spec that specify *exactly* what a PDF view must do in terms of exact appearance. Viewer programs have a certain amount of leeway. And certain things are not specified in the PDF reference (such as the exact glyphs for the standard fonts).

Not likely.