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 with [source](https://askubuntu.com/questions/1081895/trouble-with-batch-conversion-of-png-to-pdf-using-convert)