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Hi Federico,

I just want to add that when it works it does exactly what it should do with a linearized pdf and is pretty quick when compared with the best one of the other PDF libraries I've tested (PDFTron).

Luca Severini

Dear Luca,
We've just uploaded a new Radaee's iOS SDK beta that will solve http issue, you could find it here
Please tell us if something goes wrong.

Hi Federico,

The version 4.1-beta4 doesn't crash anymore. I tried with different PDF files in different conditions. That's good!

What I think is not entirely correct is that with a linearized PDF, while the first pages are loaded and showed almost immediately as expected, the remaining pages are not loaded until they don't need to be showed. The same seems to be with thumbnails.
This makes the use of linearization less useful as the big advantage of a linearized PDF file is to make the first pages (and thumbnails) available right on so the user can start reading them while the remaining pages are loaded in the background.
Doing so the user has good chance to have the page he wants to read already loaded and showed immediately without any waiting.

In other words:
With a normal (not linearized) PDF:
The file is loaded starting from beginning to the end and nothing is showed until is loaded completely.

With a linearized PDF:
The file is loaded starting from the first pages and thumbnails that are showed as soon as possible and continue (in the background) until is loaded completely.
The thumbnails should all be read and rendered asap so that scrolling to them is as smooth as possible.
When the user jump to some page, that page is loaded and showed asap.

Of course the well-done reader has a cache mechanism so the same file is not loaded again next time. To save the PDF somewhere to be reused is up to the developer of the reader.

I hope to have explained well enough. Let me know if I haven't.

Luca Severini

Hi Luca,
Which render mode are you using?
I suggest you to use single page mode, it should help the first page's render beacuse it should generate a smaller bitmap.
This will not influence other pages' render

Hi Federico,

Render mode is set to 3 that should be Single page Horizontal.
However, depending on the content, the user may want to use double page and switch between them.

I have few more questions in the attempt to be able to use your library/SDK for our PDF reader.

For what I can see in the example, thumbnails are not JPEG or PNG (or any other image type) but just the pdf page rendered in a smaller view. Am I right?
For our reader the thumbnails should be generated as images asap and kept in the storage to be used when the thumbnail list is scrolled. That's also how other PDF libraries usually work.
Is there a way from your library sdk to generate JPEG or PNG thumbnails on iOS?

I've found methods -(bool)renderThumb:(PDFDIB *)dib and Page_renderThumb(m_page, [dib handle]) but documentation doesn't say much about those two methods and what a DIB is on iOS (I remember DIB is Device-Independent-Bitmap on Windows).
Is there more documentation somewhere? What is that DIB on iOS?

Knowing what a DIB is on iOS and its structure should be possible to generate a JPEG/PNG from it.
May you explain how to generate a JEPEG/PNG thumbnail in iOS?

Thank you!

Luca Severini

Hi Federico,

Latest news...

Looking at the source files, I found the code to generate a PNG preview and adapted it to my needs.
Now the previews for all pages are generated immediately after the document is opened and that also force all document to be read in advance.
As I said before, it seems that the thumbnails are rendered as small pages every time.
So I found myself all the answers I asked earlier. What I still need to do is to use those PNG to draw the thumbnails...

Luca