Publishing Workflow – Math content as paths vs glyphs in generated PDF files

pablofe — Thu, 03 Apr 2008 01:10:00 GMT

Recently I was involved in diagnosing an issue where, when a PDF file was generated from Word 2007, the Math content from the Word document was being converted to paths, instead of being represented by glyphs from the Cambria Math font.

Note that you can download a free add-in to generate PDF files from Word 2007 from here. Also, Word 2007 has quite a bit of new Math functionality, and a beautiful font to go along with it (Cambria Math).

When the goal is to generate high quality content, whether Math content is represented as paths or glyphs makes a difference. Note that this is not something that a casual observer would necessarily notice, as seen in these screen shots at 100% magnification.

The first screenshot is from the content in Word. The second is of the generated PDF file with the content as paths. The third image is of the generated PDF file with the content as glyphs. There is very little difference in the three screen shots below (at least to me).

Original content in Word

Path based content in Adobe’s PDF viewer (100% zoom)

Glyph based content in Adobe’s PDF viewer (100% zoom)

However, when zooming in at 600%, it is possible to start noticing that, in the case where paths were used, the curves have discrete line segments, whereas the glyph version continues to be smooth.

Path based content at 600%magnification, note the aliasing on the curved segments.

Glyph based content at 600% magnification, perfect!

Initially we could not reproduce the problem in our environment over here (let me tell you how much I hate it when we cannot reproduce bugs). In talking to the folks that reported the problem, we verified that the fonts were correctly installed and the font file versions were as expected. Folks in the Word team then tracked down under which conditions paths would get generated, and we also found out that the original problem was being seen on a Windows Server 2003 installation, not on a client configuration. Note that this is not an issue that one would run into with Windows Vista, because it has a different default configuration.

From there it was straightforward to verify and solve the problem. When exporting content, Word checks whether Complex Scripts or Far East scripts are enabled on the machine, to decide whether to generate paths or glyphs for Math content. In case you run into a similar issue, the solution was to enable both scripts on the server (which may require the installation disk and a reboot), through the Languages tab in the Regional Settings control panel.

It is nice to have a happy ending to problems, and in this case being able to preserve high quality Math content.

ex Scientia : PDF

Publishing Workflow – Math content as paths vs glyphs in generated PDF files