Facial expression analysis
FaceReader has been trained to classify expressions in one of the following categories:
These emotional categories have been described by Ekman  as the basic
or universal emotions. Additionally FaceReader can classify Valence a measure of the positive of negative attitude of your participants towards your content, and Arousal which indicates the level of excitement you content induces with your participants.
The FaceReader engine has been in development for about 20 years, improving recognition accuracy year over year.
Please visit the product description page at VicarVision or Noldus if you wish to read more about FaceReader.
Below you will find a description of the different steps of the algorithm.