The data can come from manually entered text or data that has already been collected. The Switch client can be used to make data entry simple and have that data submitted with one or many images for updating. The Switch client creates an xml file of the data entered and submits it with the files. If data already exists Switch can use its scripting capabilities to create an xml file to be used in updating files.
In xml form information can be dynamically added to the File Info fields that make of the xmp data in image files. This includes the IPTC data, Categories and SubCategories.
A second script can be added to the Command section. The job can open automatically but a task can be performed while it is open using outside information passed from Switch to the arguments listed. The arguments can use the Switch built in variables as well as the parsed xml data. This is how we can automate the update of file information into the image.
Finally the file can be saved automatically to a specific format or a third script can be used to save with specified settings. The file will probably be saved the way it came in since we are only updating the file info.