Face analysis in a real-world environment is a complex task as it should deal with challenging problems such as pose variations,
illumination changes and complex backgrounds. The use of active appearance models for facial features detection
is often successful in restricted environments, but the performance decreases when applied in unconstrained environments.
Therefore, in this paper, we introduce a novel method that integrates the knowledge of a face detector inside the shape and
the appearance models by using what we call a 'virtual structuring element' (VSE). In this way the possible settings of the
active appearance models are constrained in an appearance-driven manner. The use of a virtual structuring element in an
active appearance model provides increased performance in both accuracy and robustness over standard active appearance
models applied to different environments.