org.nuxeo.ecm.platform.thumbnail.commandline.imagemagick convert -quiet -strip -thumbnail #{size} -background transparent -gravity center -format png -quality 75 #{inputFilePath}[0] #{outputFilePath} -quiet -strip -thumbnail #{size} -background transparent -gravity center -format png -quality 75 #{inputFilePath}[0] #{outputFilePath} You need to install ImageMagick.