Handling (remapping) missing/problematic (CID/CJK) fonts in PDF with ghostscript?
fonts, ghostscript, pdf
Solution
OK point 1; you CANNOT use Ghostscript and pdfwrite to create a PDF file 'without any additional processing'.
The way that pdfwrite and Ghostscript work is to fully interpret the incoming data (PostScript, PDF, XPS, PCL, whatever), creating a series of graphics primitives, which are passed to the pdfwrite device. The pdfwrite device then reassembles these into a brand new PDF file.
So its not possible to take a PDF file as input and manipulate it, it will always create a new file.
Now, I would suggest that you upgrade your 9.02 Ghostscript to 9.05 to start with. Missing CIDFonts are much better handled in 9.05 (and will be further improved in 9.06 later this year). (The font you are missing 'Osaka Mono' is in fact a CIDFont, not a regular font)
Using the current bleeding edge Ghostscript code produces a PDF file for me which has the missing font embedded. I can't tell if this will work for you because my copy of evince renders the original file perfectly well.
Added later
Examining the original PDF file I see that the fonts there are indeed embedded (as I would expect, since they are subsets). So in fact as you say in your own answer above, the problem is not font embedding, but the use of CIDFonts.
My answer here will not help you, as pdfwrite will still produce a CIDFont in the output. Basically this is a flaw in your version or installation of evince.
The problem with 'remapping' the characters is that a font is limited to 256 glyphs, while a CIDFont has effectively no limit. So there is no way to put a CIDFont into a Font. The only way to do this would be to create multiple Fonts each of which contained a portion of the original, and then switch between them as required. Slow and klunky.
If you convert to PostScript using the ps2write device then it will do this for you, but you stand a great risk that in the process it will convert the vector glyph data into bitmaps, which will not scale well.
Fundamentally you can't really achieve what you want to do (convert 1 CIDFont into N regular Fonts) with Ghostscript, or in fact with any other tool that I know of. While its technically possible, there is no real point since all PDF consumers should be able to handle CIDFonts. If they can't then its a bug in the PDF consumer.
Problem
In brief, I'm dealing with a problematic PDF, which: - Cannot be fully rendered in a document viewer like `evince`, because of missing font information; - However - `ghostscript` can fully render the same PDF. Thus -- regardless of what `ghostscript` uses to fill in the blanks (maybe fallback glyphs, or a different method to accessing fonts) -- I'd like to be able to use `ghostscript` to produce ("distill") an output PDF, where pretty much nothing will be changed, except font information added, so `evince` can render the same document in the same manner as `ghostscript` can. My question is thus - is this possible to do at all; and if so, what would be command line be to achieve something like that? Many thanks in advance for any answers, Cheers! Details: I'm actually on an older Ubuntu 10.04, and I might be experiencing - not a bug - but an installation problem with `evince` (lack of `poppler-data` package), as noted in Bug #386008 “Some fonts fail to display due to “Unknown font tag...” : Bugs : “poppler” package : Ubuntu. However, that is exactly what I'd like to handle, so I'll use the `fontspec.pdf` attached to that post ("PDF triggering the bug.", // v.) to demonstrate the problem. `evince` First, I open this pdf's page 3 in `evince`; and `evince` complains: ``` $ evince --page-label=3 fontspec.pdf Error: Missing language pack for 'Adobe-Japan1' mapping Error: Unknown font tag 'F5.1' Error (7597): No font in show Error: Unknown font tag 'F5.1' Error (7630): No font in show Error: Unknown font tag 'F5.1' Error (7660): No font in show Error: Unknown font tag 'F5.1' ... ``` The rendering looks like this: ... and it is obvious that some font shapes are missing. Adobe `acroread` Just a note on how Adobe's Acrobat Reader for Linux behaves; the following command line: ``` $ ./Adobe/Reader9/bin/acroread /a "page=3" fontspec.pdf ``` ... generates no output to terminal whatsoever (for more on `/a` switch, see Man page acroread) -- and the program has absolutely no problem displaying the fonts. Also, while I'd like to avoid the roundtrip to postscript - however, note that `acroread` itself can be used to convert a PDF to postscript: ``` $ ./Adobe/Reader9/bin/acroread -v 9.5.1 $ ./Adobe/Reader9/bin/acroread -toPostScript \ -rotateAndCenter -choosePaperByPDFPageSize \ -start 3 -end 3 \ -level3 -transQuality 5 \ -optimizeForSpeed -saveVM \ fontspec.pdf ./ ``` Again, the above command line will generate no output to terminal; `-optimizeForSpeed -saveVM` are there because apparently they deal with fonts; the last argument `./` is the output directory (output file is automatically called `fontspec.ps`). Now, `evince` can display the previously missing fonts in the `fontspec.ps` output - but again complains: ``` $ evince fontspec.ps GPL Ghostscript 9.02: Error: Font Renderer Plugin ( FreeType ) return code = -1 GPL Ghostscript 9.02: Error: Font Renderer Plugin ( FreeType ) return code = -1 ... ``` ... and furthermore, all text seems to be flattened to curves in the postscript - so now one cannot select the text in the .ps file in `evince` anymore (note that the .ps file cannot be opened in `acroread`). However, one can convert this .ps back into .pdf again: ``` $ pstopdf fontspec.ps # note, `pstopdf` has no output filename option; # it will automatically choose 'fontspec.pdf', # and overwrite previous 'fontspec.pdf' in # the same directory ``` ... and now the text in the output of `pstopdf` is selectable in `evince`, all fonts are there, and `evince` doesn't complain anymore. However, as I noted, I'd like to avoid roundtrip to postscript files altogether. `display` (from `imagemagick`) We can also observe the page in the same document with `imagemagick`s `display` (note that image panning from the commandline using 'display' is apparently still not available, so I've used `-crop` below to adjust the viewport): ``` $ display -density 150 -crop 740x450+280+200 fontspec.pdf[2] **** Warning: considering '0000000000 00000 n' as a free entry. ... **** This file had errors that were repaired or ignored. **** The file was produced by: **** >>>> Mac OS X 10.5.4 Quartz PDFContext <<<< **** Please notify the author of the software that produced this **** file that it does not conform to Adobe's published PDF **** specification. ``` ... which generates some `ghostscrip`ish errors - and results with something like this: ... where it's obvious that the missing fonts that `evince` couldn't render, are now shown here, with `imagemagick`s `display`, properly. `ghostscript` Finally, we can use ghostscript as x11 viewer itself -- to observe the same page, same document: ``` $ gs -sDevice=x11 -g740x450 -r150x150 -dFirstPage=3 \ -c '<</PageOffset [-120 520]>> setpagedevice' \ -f fontspec.pdf GPL Ghostscript 9.02 (2011-03-30) Copyright (C) 2010 Artifex Software, Inc. All rights reserved. This software comes with NO WARRANTY: see the file PUBLIC for details. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. Processing pages 3 through 74. Page 3 >>showpage, press <return> to continue<< ^C ``` ... and results with this output: In conclusion: `ghostscript` (and apparently by extension, `imagemagick`) can seemingly find the missing font (or at least some replacement for it), and render a page with that -- even if `evince` fails at that for the same document. I would, therefore, simply like to export a PDF version from `ghostscript`, that would have only the missing fonts embedded, and no other processing; so I try this: ``` $ gs -dBATCH -dNOPAUSE -dSAFER \ -dEmbedAllFonts -dSubsetFonts=true -dMaxSubsetPct=99 \ -dAutoFilterMonoImages=false \ -dAutoFilterGrayImages=false \ -dAutoFilterColorImages=false \ -dDownsampleColorImages=false \ -dDownsampleGrayImages=false \ -dDownsampleMonoImages=false \ -sDEVICE=pdfwrite \ -dFirstPage=3 -dLastPage=3 \ -sOutputFile=mypg3out.pdf -f fontspec.pdf GPL Ghostscript 9.02 (2011-03-30) Copyright (C) 2010 Artifex Software, Inc. All rights reserved. This software comes with NO WARRANTY: see the file PUBLIC for details. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. **** Warning: considering '0000000000 00000 n' as a free entry. Processing pages 3 through 3. Page 3 **** This file had errors that were repaired or ignored. **** The file was produced by: **** >>>> Mac OS X 10.5.4 Quartz PDFContext <<<< **** Please notify the author of the software that produced this **** file that it does not conform to Adobe's published PDF **** specification. ``` ... but it doesn't work - the output file `mypg3out.pdf` suffers from the exact same problems in `evince` as noted previously. Note: While I'd like to avoid the postscript roundtrip, a good example of `gs` command line with from pdf to ps with font embedding is here: (#277826) pdf - How to make GhostScript PS2PDF stop subsetting fonts; but the same command line switches for .pdf to .pdf to not seem to have any effect on the problem described above.