To read and write binary values in an AEM workflow, you need to write custom steps. A custom workflow step is implemented as an OSGi bundle that you can build using Maven and the AEM Workflow APIs that belong to the com.adobe.granite.workflow.exec package. For information, see Package com.adobe.granite.workflow.exec.
To demonstrate how to pass values in a workflow between steps, this article uses the following workflow model.
To read this development article, click https://helpx.adobe.com/experience-manager/using/workflow_passing_binary.html.