Transforming PDF to high quality jpg - extending ImageMagick

loftux — Thu, 20 Feb 2014 09:11:37 GMT

I need to transform PDF (scanned documents) to jpg image for preview using thumbnails. The default output is barely readable.I've found that you can get better output if you useconvert -density 300 source.pdf -quality 80 target.jpg‍For the standard ImageMagick thirdparty subsystem you can add comman

Re: Transforming PDF to high quality jpg - extending ImageMagick

loftux — Thu, 20 Feb 2014 13:13:56 GMT

I did this to solve this

Added new transformer ImageMagickPDF, it has the extra parameter for -density 300.
Created new class ExtendedImageMagickContentTransformerWorker, it is the same code as ImageMagickContentTransformerWorker, except for
<java>
    @Override
    public void afterPropertiesSet()
    {
        // Override and always return true
        setAvailable(true);
    }
</java>
This is since the extra parameter only works with pdf source files, the default test is gif->png it will fail. I will just assume it is available and working.
Added -context.xml file to make sure the new thirdparty transformer is loading.
Then added configuration to alfresco-global.properties (last in this post) that makes sure this new transformer is used for pdf:s to png/jpg transformation. Note that ImageMagick doesn't support direct transformation of pdf to jpg but first transforms to png. This is a limitation set by Alfresco. So the transformation is pipelined first with the new transformer, then the original (as this is image to image and cannot use the -density option).

<code title="susbystems/thirdparty/default/default/imagemagickpdf-transform-context.xml" language="xml">
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE beans PUBLIC '-//SPRING//DTD BEAN//EN' 'http://www.springframework.org/dtd/spring-beans.dtd'>
<beans>

   <bean id="transformer.worker.ImageMagickPDF" class="se.loftux.repo.content.transform.magick.ExtendedImageMagickContentTransformerWorker">
      <property name="mimetypeService">
         <ref bean="mimetypeService" />
      </property>
      <property name="executer">
         <bean name="transformer.ImageMagick.Command" class="org.alfresco.util.exec.RuntimeExec">
            <property name="commandsAndArguments">
               <map>
                  <entry key=".*">
                     <list>
                        <value>${img.exe}</value>
                        <value>SPLIT:-density 300</value>
                        <value>${source}</value>
                        <value>SPLIT:${options}</value>
                        <value>${target}</value>
                     </list>
                  </entry>
               </map>
            </property>
            <property name="processProperties">
               <map>
                  <entry key="MAGICK_HOME">
                     <value>${img.root}</value>
                  </entry>
                  <entry key="MAGICK_CODER_MODULE_PATH">
                     <value>${img.coders}</value>
                  </entry>
                  <entry key="MAGICK_CONFIGURE_PATH">
                     <value>${img.config}</value>
                  </entry>
                  <entry key="GS_LIB">
                     <value>${img.gslib}</value>
                  </entry>
                  <entry key="DYLD_FALLBACK_LIBRARY_PATH">
                     <value>${img.dyn}</value>
                  </entry>
                  <entry key="LD_LIBRARY_PATH">
                     <value>${img.dyn}</value>
                  </entry>
               </map>
            </property>
            <property name="defaultProperties">
               <props>
                  <prop key="options"></prop>
               </props>
            </property>
            <property name="errorCodes" >
               <!– The published error and fatal error codes are in the 400 and 700 ranges, but 1 is the most common and have seen 255 (could that by -1) –>
               <value>1,2,255,400,405,410,415,420,425,430,435,440,450,455,460,465,470,475,480,485,490,495,499,700,705,710,715,720,725,730,735,740,750,755,760,765,770,775,780,785,790,795,799</value>
            </property>
         </bean>
      </property>
      <property name="checkCommand">
         <bean name="transformer.ImageMagick.CheckCommand" class="org.alfresco.util.exec.RuntimeExec">
            <property name="commandsAndArguments">
               <map>
                  <entry key=".*">
                     <list>
                        <value>${img.exe}</value>
                        <value>-version</value>
                     </list>
                  </entry>
               </map>
            </property>
         </bean>
      </property>
   </bean>
</beans>
</code>

<code title="extension/somename-context.xml Load transformer and new thumbnails" language="xml">
   <bean id="transformer.worker.ImageMagickPDF" class="org.alfresco.repo.management.subsystems.SubsystemProxyFactory">
      <property name="sourceApplicationContextFactory">
         <ref bean="thirdparty" />
      </property>
      <property name="sourceBeanName">
         <value>transformer.worker.ImageMagickPDF</value>
      </property>
      <property name="interfaces">
         <list>
            <value>org.alfresco.repo.content.transform.ContentTransformerWorker</value>
         </list>
      </property>
   </bean>

   <bean id="transformer.ImageMagickPDF" class="org.alfresco.repo.content.transform.ProxyContentTransformer" parent="baseContentTransformer">
      <property name="worker">
         <ref bean="transformer.worker.ImageMagickPDF" />
      </property>
   </bean>

   <bean id="thumbnailTAMArkivOverlaypreview.registry" class="org.alfresco.repo.thumbnail.ThumbnailDefinitionSpringRegisterer">
      <property name="thumbnailRegistry" ref="thumbnailRegistry" />
      <property name="thumbnailDefinition">
         <bean id="thumbnailTAMArkivOverlaypreview" class="org.alfresco.repo.thumbnail.ThumbnailDefinition">
            <property name="name" value="overlay_preview" />
            <property name="mimetype" value="image/jpeg"/>
            <property name="transformationOptions">
               <bean parent="defaultImageTransformationOptions">
                  <property name="resizeOptions">
                     <bean parent="defaultImageResizeOptions">
                        <property name="height" value="700"/>
                        <property name="width" value="630"/>
                        <property name="allowEnlargement" value="true" />
                        <property name="maintainAspectRatio" value="true" />
                     </bean>
                  </property>
                  <property name="commandOptions">
                     <value>-quality 80</value>
                  </property>
               </bean>
            </property>
            <property name="placeHolderResourcePath" value="alfresco/thumbnail/thumbnail_placeholder_630.jpg" />
            <property name="runAs" value="System"/>
            <property name="failureHandlingOptions" ref="standardFailureOptions"/>
         </bean>
      </property>
   </bean>

</code>

<code title="alfresco-global.properties">
content.transformer.ImageMagickPDF.extensions.pdf.png.supported=true
content.transformer.ImageMagickPDF.extensions.pdf.png.priority=40
content.transformer.complex.PDF2.Image2.pipeline=ImageMagickPDF|png|ImageMagick
content.transformer.complex.PDF2.Image2.extensions.pdf.jpg.supported=true
content.transformer.complex.PDF2.Image2.extensions.pdf.jpg.priority=40
</code>

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Transforming PDF to high quality jpg - extending ImageMagick

Re: Transforming PDF to high quality jpg - extending ImageMagick