Thumbnails CMYK JPEGs

[tgmweb]

Thumbnails created from CMYK Jpegs are not showing in IE (Internet explorer can't show CYMK Jpegs…they appear broken). So any CMYK jpegs uploaded into share don't have thumbnails. Seeing as we're using alfresco for image management, this is quite a big deal!

Is there a way to force RGB colorspace in thumbnails (using imageMagick -colorpspace RGB argument) in the thumbnail definitions somehow, so thumnails are forced into the RGB colorspace?

[nsmith]

Hi,
Yes you can force RGB colors using the ImageMagick command -colorspace RGB. To do so you need to modify the thumbnail definition for the doclib thumbnail. This can be found in the file thumbnail-services.xml.
Find the bean definition with name 'doclib'.  Inside this definition is another bean of class ImageTransformationOptions. Add a property to this bean definition  <property name="commandOptions" value="-colorspace RGB"/> as shown below:

<!– Slingshot Document Library image thumbnail options –>
<bean class="org.alfresco.repo.thumbnail.ThumbnailDefinition">
   <property name="name" value="doclib" />
   …
   <property name="transformationOptions">
      <bean class="org.alfresco.repo.content.transform.magick.ImageResizeOptions">
         <property name="resizeOptions">
            <bean class="org.alfresco.repo.content.transform.magick.ImageResizeOptions">
               <property name="width" value="100"/>
                  …
               <property name="commandOptions" value="-colorspace RGB"/>

This commandOptions property can take any command-line ImageMagick options you wish to be applied to the thumbnail.

When the Alfresco server is restarted these changes will be applied to any new thumbnails that are generated. Existing thumbnails will not be updated, however, so will not be displayed correctly unless you update the source content to force the thumbnail to be re-rendered.

I hope that helps.