[poppler] Supporting PDF 1.6 UserUnit

[Kristian Høgsberg]

Brad Hards wrote:
> Until PDF 1.6, the universe was scaled to 72dpi. 
> 
> That isn't true anymore - there is now a per-page dictionary value that 
> specifies the resolution. It is called UserUnit (see pg 122 of the spec).
> 
> Now I don't have any PDF documents that use this, and I can't figure out how 
> to make Acrobat 7.0.2 produce one. So maybe it isn't that widely used. 
> However a quick scan of the poppler source tree suggests that this might not 
> be a fairly widespread change, so maybe we should get to it soon?
> 
> Thoughts on this?

I'm not sure we need to get this in right now.  I haven't seen any 
documents use it or heard anybody ask for this, so I'm guessing it's not 
that widely used.  Even if it's a widespread change, why does that mean 
we need it sooner rather than later?

Anyway, this sounds more negative than I wanted it too; if you want to 
look into this, that's cool.  It's just that there are more interesting 
(IMO, anyway) and more requested features such as images with image 
masks (binary transparency for images, #3098) and soft masks 
(transparent gradients, drop shadows, #3020).

cheers,
Kristian