til/command_line_utils/joining-images-to-pdf.md

You can join multiple images to pdf using convert:

convert *.png out.pdf

If you get an error like

convert-im6.q16: attempt to perform an operation not allowed by the security policy `PDF' @ error/constitute.c/IsCoderAuthorized/408.

follow the steps below:

sudo vim /etc/ImageMagick-6/policy.xml

and replace the line

<policy domain="coder" rights="none" pattern="PDF" />

with

<policy domain="coder" rights="read|write" pattern="PDF" />

source