#### Note: this recognizer runs on a web server, the video file will be uploaded using HTTP.

### How to use the Skin Tone Estimator from within ELAN

The Skin Tone Estimator recognizer by the Fraunhofer Heinrich Hertz Institute HHI allows you to analyze a video to select suitable skin tone properties for further analysis.

- Input: A video in FFMPEG supported file format (most common file formats are supported) and optionally a tier giving scene / shot timespans to be analyzed separately. If no such tier is provided, the video is processed as one long scene.
- Settings:
  - Change threshold gives control over the sensitivity to differences between video frames.
  - Use single cluster controls whether a single moving cluster in a video frame already counts as movement.
  - Logging level gives control over the amount of messages generated during processing.
- Output: The recognizer produces a special annotation tier data set with information about YUV skin tone and range, suitable as input for the Hand Head Tracking recognizer.

AVATecH and AUVIS compatible recognizers have the following categories of settings, input and output elements:

- input media: ELAN automatically uses the first suitable media file of your current annotation session, but you can change that to other supported files belonging to the session. Very few recognizers expect multiple input media files or extra input files in 'timeseries' or recognizer-specific formats.
- input tiers: Some recognizers need input in the form of an annotation tier, for example to select timespans of interest. For some recognizers, the input is expected to be the output of another recognizer. This gives you a chance to edit and correct data - often simply tiers - between the two steps.
- numerical input: Recognizers can be configurable by numerical 'knobs'. ELAN can show those as slider or field. Recognizers often work well enough with defaults already.
- choice input: Recognizers can give you the option to select settings from a pre-defined list. An example can be 'verbose/normal/silent' messages or 'high/low' sensitivity. ELAN shows drop down selectors here. In special cases, a recognizer can also have 'any text' configuration items.
- output: Recognizers often produce one or more annotation tiers. ELAN will offer to add those to your annotation session as new tiers. It is also possible for recognizers to output timeseries (which ELAN can show as curves) or even audio, video or other files. Most recognizers only produce zero or more tiers (plus log messages) as output. It is often possible to selectively skip some output steps.
- log: You can open a window showing general messages from the recognizer, tagged by type (e.g. DEBUG, INFO, WARN, ERROR, RESULT or PROGRESS). Messages of higher priority also update the processing status display, so they can be seen directly without having to review the log text.
- basic or advanced recognizer settings: ELAN gives you the choice to either hide or show 'advanced' settings. Default values will be used for those settings which are hidden.

Your default ELAN configuration invokes a CLAM REST web service wrapper on catalog.clarin.eu to have your files analyzed. In other words, your media files and, if applicable, input tiers will be uploaded for processing and ELAN will process the downloaded (tier or other) results as if you had done the processing locally. For use in situations where a web service can not be used (too large files or no internet available) you can also request a copy of the recognizer for local installation on Linux or Windows, protected by USB dongle.

For this and for general support with the use of this recognizer, please contact auvis@mpi.nl or use the ELAN and AUVIS forums on the website of The Language Archive.

CLAM, ELAN and the client-side recognizer proxy are free open source software under the GNU General Public License - however, some of the recognizers can be propietary closed source software. Licenses for academic use are available on request. Use of the web services is free at the moment, but may be limited to the academic community if it becomes necessary.