Photoshop Elements - Explorer

As a way of investigating the internals of the Adobe Photoshop Elements (PSE) meta tags, I thought I'd whip up a little Eclipse plug-in to do some experimentation.

The primary purpose was to provide a means of exporting my metadata. I do a little editing within PSE, but my largest investment is in the metadata attached to (almost) every photo.

I realize that you can (and should) backup your PSE catalog using the supplied tools, but this approach also provides a degree of independence should I ever wish to decamp to another product.

Plug-in Structure

The following diagram shows the plug-in dependency hierarchy. The diagram was produced using the brilliant Plug-in Dependency Visualization Tool from Ian Bull, also described here on his blog.



As can be seen from the hierarchy, I make use of a number of libraries, packaged as plug-ins.

• XOM - to provide XML support. See here for more details on XOM.
• SQLite JDBC driver. See here for more details.
  

I had a few choices about how I was going to deploy it - workbench, RCP or even scriptable via Eclipse Monkey ... but I thought the workbench plug-in would be the simplest thing to get started.

Workbench Integration

Since I was aiming for the workbench, it made sense to provide some integration with the functionality you get for free! The two most obvious points are:

• workbench properties
• an image viewer
  

It's very easy to integrate with the workbench Properties View. This is very well documented - in particular in this article.

I have also encountered a great image viewer, courtesy of Wayne Beaton - see here for more details.

The great thing about making use of these functions is that they simply require an adapter to the required class to exploit the functionality.

• the Properties View needs an adapter to an IPropertySource implementation
• the Image View plug-in requires an adapter to an ImageProvider implementation.

To keep things simple, I initially coded up the getAdapter code directly into the model - but, with a teeny bit of thought - and prompting from Wayne's latest "adapters" articles here - it made sense to extract them into an AdapterFactory. And after doing this, it made sense to extract the whole model to it's own plug-in.

Plug-in Functionality

It's pretty basic - a simple PSE Explorer View, which lists the contents of the catalog, and two menu options:

• one to load an existing PSE catalog file (SQLite database)
• one to export the loaded PSE catalog as an XML Document.

The following screen shot shows the plug-in in action - with the PSE Explorer view on the top half of the screen, and the properties and Image View on the bottom.



The plug-in functionality is initiated by the two command handlers (corresponding to the menu items) - that is, import and export.

The import function is facilitated by a simple DataProvider class. This provides the means of accessing the SQLite database and populating the model used by the viewer. The SQL used is similar to my earlier experiments.

The export function merely provides an XML transformer for the populated model. The results of the export looks like this:



Summary

This is just a starting point, but it has provided a easy way for exploring the PSE metadata. With a bit more polish, I'll see if I can release some of the code.