Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
$ convert foo.png foo.pdf && acroread foo.pdf # oops, too big by 50%
$ convert -density 110 foo.png foo.pdf && acroread foo.pdf # via eyeball check looks pretty close to orig PNG size
Now I'm starting to make wild guesses about DPI (72?) and adding 50% to make it 108, which is pretty close to my guess-and-check density magic number. I'd like to understand (at least a little): (1) why I need to specify "-density 110", and (2) if that's really the right number. Thanks!
So acroreader seems to just be throwing me off. I've made sure to set its zoom level to 100% and indeed the "big" PDF looks 50% oversized (as compared to my PNG viewer at 100%, eog). But I'll presume that "identify" is telling the truth here -- that it's really maintaining the 1280x720. The big and small PDFs are the same file size. So I don't understand why the viewers don't agree, but maybe I don't need to worry about it.
FYI, this PDF is to be uploaded to SlideShare.com and I'm wanting the resolution to be at a standard size. I'm going to trust "identify" for now, and go with the default density.