If a pdf file is very old, using acroread, convert(print) it to a ps file that can be opened with the emacs. For example, it is called "output.ps"
gs -q -dSAFER -dNOPAUSE -dBATCH -sDEVICE=pdfwrite --dCompatibilityLevel=1.3 sOutputFile=out.pdf
-c "[/CropBox [60 70 550 738] /PAGES pdfmark " -f output.ps
The letter size is Pts (H
792 W
612) and I want to crop left 60, right 62, top 54, bottom 70 pts. So the CropBox option is
/CropBox [a b c d]
a = 60
b = 70
c = 612-62 = 550
d = 792-54 = 738
* References
http://www.prepressure.com/library/paper-sizes
http://stackoverflow.com/questions/6183479/cropping-a-pdf-using-ghostscript-9-01
* Note that unfortunately, the Amazon kindle opens this modified pdf extremely slow.