How do I control PDF paper size with ImageMagick?

I have 16 jpg files which are around 920x1200 pixels (the widths slightly differ but heights are all 1200). I'm trying to join them into a pdf with:

convert *.jpg foo.pdf

But the resulting paper size is 1.53x2 inches. If I pass the arguments -page Letter, the page size ends up being a bewildering 1.02x1.32 inches. What is going wrong here? All of the information I can find suggests that this should work. I just want a document that consists of 16 letter-size pages.

This question is pretty old, but I had a similar problem and I think I found the solution.

The documentation for the -page option says "This option is used in concert with -density", but the relationship between the options seems a little unclear, possibly because the documentation is geared towards raster images.

From experimenting with the settings, I found that the pdf page size can be controlled by combining -page -density and -units. The documentation for -page shows that letter is the same as entering 612 x 792. Combining -density 72 with -units pixelsperinch will give you (612px /72px) * 1in = 8.5in.

convert *.jpg -units pixelsperinch -density 72 -page letter foo.pdf should do what the original poster wanted.

I just succeeded with convert file.mng -page letter file.pdf

For Letter, you need to specify the size as 792x612 PostScript points. Therefor try this command:

 convert \
    in1.jpg \
    in2.jpg \
    in3.jpg \
    in4.jpg \
    in5.jpg \
   -gravity center \
   -resize 792x612\! \
    letter.pdf

Works for me with ImageMagick version 6.7.8-3 2012-07-19 Q16 on Mac OS X:

identify -format "%f[%s] :  %W x %H\n" letter.pdf
letter.pdf[0] :  792 x 612
letter.pdf[1] :  792 x 612
letter.pdf[2] :  792 x 612
letter.pdf[3] :  792 x 612
letter.pdf[4] :  792 x 612

Or

pdfinfo -f 1 -l 5 letter.pdf
Title:          _
Producer:       ImageMagick 6.7.8-3 2012-07-19 Q16 http://www.imagemagick.org
CreationDate:   Fri Jul 27 22:28:00 2012
ModDate:        Fri Jul 27 22:28:00 2012
Tagged:         no
Form:           none
Pages:          5
Encrypted:      no
Page    1 size: 792 x 612 pts (letter)
Page    1 rot:  0
Page    2 size: 792 x 612 pts (letter)
Page    2 rot:  0
Page    3 size: 792 x 612 pts (letter)
Page    3 rot:  0
Page    4 size: 792 x 612 pts (letter)
Page    4 rot:  0
Page    5 size: 792 x 612 pts (letter)
Page    5 rot:  0
File size:      178642 bytes
Optimized:      no
PDF version:    1.3

According to this, 72 dpi is the default density => one dot per pixel (for a computer screen).

So you just need to specify -units pixelsperinch.

You can type the following command :

$ convert *.jpg -units pixelsperinch -page letter foo.pdf

BTW : If you want to use a non standard page size such as A4R for example, you must first determine the page size in dots (or pixels given at 72dpi) :

$ paperconf -s -p A4
595.276 841.89

Then the -page argument will be 842x595