Re: Ghostscript/GhostPDL 9.22 Release Candidate 1

[Ken Sharp]

At 07:01 22/09/2017 +0900, Masamichi Hosoda wrote:

> If there is a full font embedded (non-subset) PDF,
> does the bigpdfs trick work effectively?

Its still, in my opinion, a risky thing to do. However, if the font were 
fully embedded, you wouldn't need to use Ghostscript and the 
PDFDontUseFontObjectNum bug approach (which is the risky part).

Because the fonts would be genuinely identical, MuPDF would be able to spot 
the font streams at least as being the same and would be able to reliably 
remove the duplicates.

The Font and FontDescriptor dictionaries might not be possible to remove, 
so the effect wouldn't be quite as good as the current approach, but these 
dictionaries run to a few tens or at most a few hundred bytes. The FontFile 
streams are where most of the space is going, and those would be possible 
to remove, if they were truly duplicates.


> Or, even so, should we take other methods (e.g. using non-embedded PDFs)?

I'm not sure what other methods there would be. Using EPS inclusions would 
have the same effect as PDF. Rendering to bitmaps would be (I'd guess) as 
large as the PDF files, and would suffer from non-scalability.

Converting to TeX format would probably work, but apparently there were 
problems with that.

Is there some other approach available ?


                    Ken