Утилита convert из пакета ImageMagick позволяет легко создать многостраничный pdf документ из набора png, jpg или других графических файлов. На этом возможности утилиты convert не ограничиваются.

Собрать несколько графических файлов в один многостраничный pdf документ можно командой

convert 'file1.jpg' 'file2.jpg' 'file3.jpg' 'file.pdf'

Если работа команды convert заканчивается ошибкой:

convert-im6.q16: not authorized `Паспорт1.pdf' @ error/constitute.c/WriteImage/1037.

Поправьте файл политик /etc/ImageMagick-6/policy.xml Закоментируйте строку

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

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE policymap [
<!ELEMENT policymap (policy)+>
<!ELEMENT policy (#PCDATA)>
<!ATTLIST policy domain (delegate|coder|filter|path|resource) #IMPLIED>
<!ATTLIST policy name CDATA #IMPLIED>
<!ATTLIST policy rights CDATA #IMPLIED>
<!ATTLIST policy pattern CDATA #IMPLIED>
<!ATTLIST policy value CDATA #IMPLIED>
]>
<!--
  Configure ImageMagick policies.

  Domains include system, delegate, coder, filter, path, or resource.

  Rights include none, read, write, and execute.  Use | to combine them,
  for example: "read | write" to permit read from, or write to, a path.

  Use a glob expression as a pattern.

  Suppose we do not want users to process MPEG video images:

    <policy domain="delegate" rights="none" pattern="mpeg:decode" />

  Here we do not want users reading images from HTTP:

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

  Lets prevent users from executing any image filters:

    <policy domain="filter" rights="none" pattern="*" />

  The /repository file system is restricted to read only.  We use a glob
  expression to match all paths that start with /repository:
  
    <policy domain="path" rights="read" pattern="/repository/*" />

  Let's prevent possible exploits by removing the right to use indirect reads.

    <policy domain="path" rights="none" pattern="@*" />

  Any large image is cached to disk rather than memory:

    <policy domain="resource" name="area" value="1GB"/>

  Define arguments for the memory, map, area, width, height, and disk resources
  with SI prefixes (.e.g 100MB).  In addition, resource policies are maximums
  for each instance of ImageMagick (e.g. policy memory limit 1GB, -limit 2GB
  exceeds policy maximum so memory limit is 1GB).
-->
<policymap>
  <!-- <policy domain="resource" name="temporary-path" value="/tmp"/> -->
  <policy domain="resource" name="memory" value="256MiB"/>
  <policy domain="resource" name="map" value="512MiB"/>
  <policy domain="resource" name="width" value="16KP"/>
  <policy domain="resource" name="height" value="16KP"/>
  <policy domain="resource" name="area" value="128MB"/>
  <policy domain="resource" name="disk" value="1GiB"/>
  <!-- <policy domain="resource" name="file" value="768"/> -->
  <!-- <policy domain="resource" name="thread" value="4"/> -->
  <!-- <policy domain="resource" name="throttle" value="0"/> -->
  <!-- <policy domain="resource" name="time" value="3600"/> -->
  <!-- <policy domain="system" name="precision" value="6"/> -->
  <!-- not needed due to the need to use explicitly by mvg: -->
  <!-- <policy domain="delegate" rights="none" pattern="MVG" /> -->
  <!-- use curl -->
  <policy domain="delegate" rights="none" pattern="URL" />
  <policy domain="delegate" rights="none" pattern="HTTPS" />
  <policy domain="delegate" rights="none" pattern="HTTP" />
  <!-- in order to avoid to get image with password text -->
  <policy domain="path" rights="none" pattern="@*"/>
  <policy domain="cache" name="shared-secret" value="passphrase" stealth="true"/>
  <!-- disable ghostscript format types -->
  <policy domain="coder" rights="none" pattern="PS" />
  <policy domain="coder" rights="none" pattern="PS2" />
  <policy domain="coder" rights="none" pattern="PS3" />
  <policy domain="coder" rights="none" pattern="EPS" />
  <!-- policy domain="coder" rights="none" pattern="PDF" / -->
  <policy domain="coder" rights="none" pattern="XPS" />
</policymap>

Утилита convert может многое, например команда

convert file.jpg -crop 690x470+37+38 +repage out.jpg

обрезает файл file.jpg в размер 690х470 px с отступом от левого верхнего угла 37х38 px и сохраняет результат в файл out.jpg