4.2.Image conversion with ImageMagick

Working with the intranda TaskManager allows Goobi to outsource various CPU-intensive tasks to external devices. One such scenario in the case of digitisation projects involves generating image derivatives. For example, TaskManager can be used to generate JPG images on a separate server and transfer them back automatically to Goobi without drawing on the Goobi server’s own CPU capacity.

Starting the plugin

The following instruction shows how TaskManager can be used to generate JPG images on a separate server using ImageMagick. The instruction must be incorporated into a workflow step.

/usr/bin/java -jar /opt/digiverso/itm/bin/TaskClient.jar 
    -itm http://localhost:8080/itm/service 
    -e -i {stepid} 
    -T {processtitle} 
    -t SHELL 
    -n iii-create_jpeg 
    -s {origpath} 
    -d {processpath} 
    -gid {processid}

Parameters

The command parameters are explained in the following table:

Parameter	Possible Goobi variable	Meaning
-itm	http://localhost/itm/service	URL to the intranda TaskManager interface
-e , --returnError	-	If entered, the TaskClient will end with an error code to prevent the workflow from continuing automatically.
-p	0 – 10	Priority to execute this job
-gid	{processid}	Goobi process ID
-i	{stepid}	ID for the workflow step that launches the call
-T, --title	{processtitle}	Goobi process title for which the call is launched
-t, --jobtype	SHELL	Job type
-n, --templatename	iii-create_jpeg	Name of the configuration file to be used
-s, --source	{origpath}	Path to the master directory for the process
-d, --destination	{processpath}	Path to main process directory

Operation of the plugin

Once the image derivative has been generated, TaskManager will automatically move the newly created files into the corresponding Goobi process folder. The successful completion of this task is recorded in the process log, and the automatic workflow step is completed via WebAPI.