Re: Another possible gb.poppler bug?

[Lee <t.lee.davidson@xxxxxxxxx>]

On 12/1/25 7:52 PM, gbWilly wrote:
> On Monday, December 1st, 2025 at 23:39, Lee <t.lee.davidson@xxxxxxxxx> wrote:
[snip]
> > I may have guessed wrong about there being no Thumbs in the F16866* file. To my knowledge, Okular will not display thumbnails if
> > there are none in the document. But, it does for that file.
> >
> > What may be the issue is, that file appears to be PDF version 1.4, while the other two are 1.6 or 1.7. Perhaps the thumbnails
> > are referenced differently in the earlier version.
>
>
> 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.

I don't think PDF version is at issue. I selected six of my PDF documents that represented versions from 1.1 to 1.7 excluding 
1.2. Your demo project found thumbnails only in the 1.3 versioned document. In all the others, it found none.

And, contrary to what my research told me, I believe that Okular does indeed generate thumbnails if there are none embedded in 
the document. I viewed one particular PDF that was obviously constructed of scanned images of physical documents. It appeared 
that Okular generated thumbnails only as needed, ie. when the thumbnail for a page was scrolled into view.

So there's a suggestion. To speed up loading time of a PDF document for which no thumbnails are found, generate thumbnails only 
for those that are visible.


--
Lee

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