On Thu, 12 Dec 2013, Michael Moore wrote:

> I've got a folder of png files that I want to turn into a multi-page pdf 
> with letter-sized pages.
>
> I'm currently trying to use imagemagick, but the resulting PDF is 
> smaller than it should be. I've posted a message on ImageMagick's 
> forums,[1] but I'm wondering if I'm not just using the wrong tool in the 
> first place.
>
> Does anyone have a better tool to be using for this?
>
> [1] http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=24633


You have to know the dpi for the images:

identify -format "%x x %y\n" output/*.png | less

Are they all the same?  Are they all in PixelsPerInch?  If they are 
different, you might want to fix that by doing something like this:

mkdir output2
cd output
for file in *.png ; do convert -units PixelsPerInch -density 300 "$file" ../output2/"$file" ; done
cd ..

If the images were all the same size in pixels, you can choose the density 
to get the correct size on the page.  Otherwise you might have to run them 
one at a time or in groups.

I would stick with convert, when possible.  If it sometimes gives a bad 
result, I think that's because there is a trick you haven't learned yet.

Mike