Re: Another possible gb.poppler bug?

[Claus Dietrich <claus.dietrich@xxxxxxxxxx>]

Am 01.12.25 um 23:07 schrieb gbWilly:
> Are you sure most pdf files have no thumbnails as most pdfviewers seem 
> to show them for most pdf files, kind of the other way around.

Yes. Just check what apps have the capability to generate PDF 
thumbnails. This why I needed Windows and Adobe Acrobat to generate a 
test file with embedded thumbnails.

> I have a 177 page document that opens before I can count to 1 with 
> thumbnails. Self rendering when opening that file means I can count to 
> 3 before it is openen and thumbnails show. 

Why would you render it yourself if embedded thumbnails are there? Just 
use them (and our Gambas apps are doing it).

Am 02.12.25 um 00:16 schrieb Benoît Minisini:
> The PDF viewer must be modified to be clever, and render the thumbnail 
> only when needed.

It doesn't need be modified - it is doing it already. This why I am not 
sure what this is all about.

In my experience our Gambas apps reliably load embedded thumbnails if 
there are some and the loading is of cause much quicker in that case.

PDF viewers like XReader or Okular won't provide you with any proof that 
the loaded PDF has embedded thumbnails. If you just look on loading 
times then start with a comparison of XReader and Okular. Sometimes 
there are very huge differences for whatever reason.

Am 02.12.25 um 01:52 schrieb gbWilly:
> That exactly what I mean. I have the idea that there are thumbs in several of the files I open, the self render is just a workaround for when nor thumbs are found internal.
> And just as with the pages, could there something missing (another reference as you say) that prevents from retrieving the thumbs in certain files. That is what I would like to know.

So far I haven't seen any proof that the PDF files in question have 
embedded thumbnails which gb.poppler doesn't find.

In my practice I noticed that embedded thumbnails generated by Adobe 
Acrobat don't look as good because of their low resolution. The 
resolution it kept low to increase the loading speed and to keep the 
resulting PDF file size small.  The generation of thumbnails is optional 
in Adobe Acrobat and when you generate them with a higher resolution the 
file size is exploding and becomes less suitable for the web or emails. 
The thumbnails of the files discussed here rather seem to be self 
rendered by the viewers. So I tend to believe that they don't have 
embedded thumbnails.

Best regards, Claus