The AUCoderDemo application now uses a simple plugin system for managing different types of expression detectors. There are several different types of detectors which run at different stages, but for the most part, they can all be treated the same. One exception is that some detectors require the presence of others. There is currently no warning if pre-requisites are not present.

The following is a list of plugins that may be present:
CERT1Weights.bundle (AUs 1, 2, 4, 5, 10, 12, 14, 20)
EmotionDetectorPlugin.bundle (Various fear and distress detectors)
BlinkDetector.bundle
SmileDetectorPlugin.bundle
AdditionalAUs.bundle (AUs 25, 17, 7, 6, 26, 15, 24, 23, 27, 18, 9, 28)
AdditionalAUs2.bundle (AUs 16, 11, 38, 30, 19, 8, 39, 22, 32, 13)
MLR: 1+2+4 (requires CERT1Weights and EmotionDetectorPlugin)
MLR: 1-2 (requires CERT1Weights and EmotionDetectorPlugin)

Each plugin can be disabled using the Finder's 'Get Info...' menu item. Click on the CERT application's icon in the finder and choose 'Get Info...' from the File menu. One of the sections of the Get Info window is 'Plug-ins:'.  Deselecting a plugin will disable it, preventing it from loading the next time the application is run. Changes in this window don't have any effect when the application is already running, until it is restarted.

For any plugins that are not already installed inside the application itself there are two methods of adding them. One method is to use the 'Add...' button of the 'Plug-ins' section of the CERT application's Get Info window to copy one or both plugins to the application itself. A second option is to move or copy one or both plugins to one of the specific Library folders. The folder path is Library/Application Support/MPLab/PlugIns. That can be either in an individual user's home directory (in which case it will only be available for that user), or at the top level of the hard drive (in which case it will be available for every user on the system). In either case, some or all of the folders (except Library) may need to be created.

When the application is running, individual plugins can be enabled or disabled by going to the 'Plugins' pane of the preference window (Preferences menu item under the AUCoderDemo menu). This option only prevents a plugin from running, any data files will still be loaded when the application is launched.

There is a new type of plugin called "Feature Detector". The two eye feature detectors are being used to replace the old face/eye detector (as of version 2.4). Those two are required and can't be disabled. In addition, other feature detectors can be added, removed, enabled and disabled like any other plugin. Results from the feature detectors will show up in the main image window along with the face and eye locations.