[poppler] pdftoppm: resulting image dpi and/or size is unexpected

[Albert Astals Cid]

El Dilluns, 7 de maig de 2012, a les 19:14:54, Carlos Fernandez va escriure:
> Albert,
> 
> Thanks for the quick reply.

Please don't answer me, answer to the list, there's no reason to keep the 
discussion "hidden" to the rest of the world.

> I am reading the DPI and image dimensions from Preview on OS X.  It
> reports the fractions DPI for the 2040x2640 image.  Is the DPI
> information baked into the image as metadata?

No idea to be honest.

> >> using "-r 150" (or just relying on the default value of 150) to create
> >> an image on a 8.5x11 inch pdf generates an image that is 1275 × 1651
> >> pixels at 150dpi.
> 
> Should this image be 1275x1650?

That might make sense.

Anyway this is a development list, if you are not planning to develop a fix 
what you should do is open a bug in bugzilla, it is much easier to keep track 
of the bugs in there.

Cheers,
  Albert

> 
> Carlos
> 
> On Mon, May 7, 2012 at 5:17 PM, Albert Astals Cid <aacid at kde.org> wrote:
> > El Dilluns, 7 de maig de 2012, a les 16:58:27, Carlos Fernandez va 
escriure:
> >> trying to split a pdf into page images using pdftoppm.  I would like
> >> the resulting images to maintain the same size and scale as the source
> >> PDF.  unfortunately the images being generated are somewhat
> >> unexpected.
> >> 
> >> using "-r 150" (or just relying on the default value of 150) to create
> >> an image on a 8.5x11 inch pdf generates an image that is 1275 × 1651
> >> pixels at 150dpi.
> >> 
> >> using "-r 240" to create an image on the same 8.5x11 inch pdf
> >> generates an image that is 2040 x 2640 pixels at 239.97 dpi.
> > 
> > Hmmm, really?
> > 2040/8.5 = 240 not 239.97
> > 2640/11 = 240 not 239.97
> > 
> >> these results were consistent for png or tiff output.  I got similar
> >> results for other dpi settings across a few different PDFs.
> >> 
> >> What can i do to get more consistent results?
> > 
> > What's inconsistent?
> > 
> > Albert
> > 
> >> Carlos
> >> _______________________________________________
> >> poppler mailing list
> >> poppler at lists.freedesktop.org
> >> http://lists.freedesktop.org/mailman/listinfo/poppler
> > 
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