[XeTeX] Size of PDF files produced by XeTeX

[Jonathan Kew]

On 31 May 2006, at 4:07 pm, Bruno Voisin wrote:

> With identical input, save for the choice of fonts, pdfTeX produces
> output that seems generally significantly smaller than XeTeX, at
> least on Mac OS X.
>
> [snip]
>
> Does this mean the included graphics, in JPEG and PDF formats, are
> first uncompressed by pdfTeX and XeTeX then recompressed at the end
> of the process,

I don't know if this actually happens in all cases, or if there are  
some situations (with either program) where the JPEG data is copied  
unchanged to the output. From your stats, it looks as though XeTeX  
(or rather Quartz), at least, is recompressing, but less tightly than  
your original files. :(

> and that pdfTeX compression would be more efficient
> than that offered by xdv2pdf (which possibly calls Quartz routines)?

Yes, it does. In effect, what it does is a "print to PDF" rendering  
of the document, through Quartz.

> And in that case, is there some special invocation of xvd2pdf that
> would make the compression more efficient?

There's no direct way to control this through xdv2pdf, I'm afraid.  
You get whatever Apple decided was appropriate for a print spool  
file, which does not seem to be optimized for size.

> The problem here is that the note was meant to be emailed or put on a
> ftp server for download, so that size matters, eventually. I'll
> probably just burn a CD and use standard mail, as requested by the
> recipient, but I was wondering whether a better solution existed.

You could try opening the PDF in Preview and saving a new copy with  
the "Reduce File Size" Quartz filter enabled (via the Save As dialog  
in Preview), or using the "Compress PDF" option from the Print  
dialog. I don't know exactly what effect each of these will have;  
you'll want to review the results and see if the graphics are still  
of a suitable quality, as I guess they'll affect the JPEG compression.

JK