What kinds of facial features are used in face retrieval?

An experimental evaluation of a facial image retrieval system showed that our previously proposed “context-driven retrieval mechanism” facilitated retrieval (or externalization) of ambiguous as well as better defined facial images. Some features, such as face shape, eyebrow tilt, and eye shape, were found to be more salient than others. The context-driven retrieval mechanism, while maintaining the relative importance of facial features, facilitated retrieval by reducing the variance in the less salient features