Taking Advantage of Metadata

Metadata is the information about a file that is “hidden” in its header. Many cameras add information about the photograph in its metadata when the picture is taken. Some of this information may include focal length, ISO Speed, Aperture, Shutter Speed, and even GPS information. Most designers make use of important metadata such as Capture Date and Modification Date which are also added to the metadata automatically.On top of the information recorded without intervention, there are some fields that designers should be interested in:

  • copyright information
  • document title
  • author and author title
  • description
  • keywords
  • rating

Adding Metadata

The responsibility of adding this information to image files usually falls on the person who is responsible for cropping, modifying, and saving the file (most likely in Photoshop). The extra chore of adding metadata information to an image is often met with some resistance because of workload. Even the argument that having metadata “saves time in the long run” falls on deaf ears. Often, the response might be something akin to “When one is up to their ankles in alligators, there is no time to drain the swamp.” Automating Metadata You may not be aware that you can write scripts for Photoshop using AppleScript, ExtendScript, and Visual Basic. Interestingly, Photoshop did not support AppleScript until version 7. Prior to this, a third-party plugin from MainEvent was required. Since then, Adobe’s support for scripting has grown with each release. 

For users, however, most are familiar with setting up actions in Photoshop but scripts may be another matter. Scripts are much more efficient than actions in that they access the application’s code dictionary rather than manipulating the interface. Importantly, scripts support logic, so a script can test a condition and branch to code based on this state or condition. You might decide to become your Photoshop user’s best friend with a script that takes much of the work out of adding metadata to their files. In many ways, writing the code is quite similar to coding for InDesign.

Sample Photoshop Script

Just to get you started, you might want to test out the following script with a folder in your home directory that has just a few images. Once you see how the script works, you may want to modify it to include additional information. And, of course, you will want to rewrite the getInfo handler so it returns all of the information you want the user to enter.

(*Expects image folder to be located in the user's home directory.*) 
property userName : "S Hopkins"
property userTitle : "Photographer"
property cRightNotice : "Copyright 2014, Shirley Hopkins, DTP Connection"
property ownerURL : "yourscriptdoctor.com" 

set myDirectory to path to home folder from user domain
set theFolder to choose folder with prompt "Select a folder of images" default location myDirectory
set filePath to theFolder as string
set fileList to list folder theFolder without invisibles

tell application "Adobe Photoshop CC 2014"
	repeat with i from 1 to length of fileList
		set fileName to item i of fileList
		set imageRef to (filePath & fileName)
		open file imageRef showing dialogs never
		tell current document
			set docName to name
			tell info
				set author to userName
				set author position to userTitle
				set copyrighted to copyrighted work
				set copyright notice to cRightNotice
				set owner url to ownerURL
				with timeout of 500 seconds
					set userInfo to my getInfo(docName)
				end timeout
				copy userInfo to {docTitle, docCaption, docKeywords}
				set title to docTitle
				set caption to docCaption
				set keywords to docKeywords
			end tell --info
		end tell -- document
	end repeat
end tell -- application

(*You will need to create a user dialog to get the information you want from the user*)
on getInfo(docName)
	set userResponse to display dialog "Enter caption" default answer "My caption here" buttons {" Cancel", "OK"} default button "OK"
	if button returned of userResponse is "OK" then
		set imgCaption to text returned of userResponse
		set imgCaption to ""
	end if
	return {docName, imgCaption, {"One", "Two", "Three"}}
end getInfo

Use File Information

Now that having a script for your user will make sure the necessary information will be written into image files, you can use the information in any number of automation workflows. The most common use is for adding a credit and caption to an image as part of the image being placed.

A handler that can be modified to return the credit and caption for a placed image follows. It expects a reference to the image placed and returns a string having both the credit and the caption. This could be modified to return whatever metadata your script might require.

getImageMeta handler

on getImageMeta(imageRef)
	tell application "Adobe InDesign CC 2014"
		set linkRef to item link of imageRef
		set linkMeta to properties of link xmp of linkRef
		if author of linkMeta is not "" then
			set capStr to author of linkMeta & return
			set hasCredit to true
		end if
		set capStr to capStr & description of linkMeta
	end tell
	return capStr
end getImageMeta

In a script for creating a multi-state object, you could use the image title and description of the metadata to add text to each state of the object. When creating a document that will be exported to HTML or ePub you will want to set up Object Export Options to generate alternate text using the file’s metadata (Title, Description, or other).

Not to be forgotten are the text variables you can set up for your InDesign documents. Many of these rely on the metadata found in an image file. Our next blog will look at some of the ways you can use text variables as part of an automated workflow.

Onward and Upward

If the idea of automating Photoshop has tweaked your interest, you will want to visit www.adobe.com/devnet/photoshop/scripting.html. There you will find links to the Photoshop CC Scripting Guide and references for working with all three scripting languages (whichever is your favorite).