Face detection based on a human attention guided multi-scale model.

Multiscale models are among the cutting-edge technologies used for face detection and recognition. An example is Deformable part-based models (DPMs), which encode a face as a multiplicity of local areas (parts) at different resolution scales and their hierarchical and spatial relationship. Although these models have proven successful and incredibly efficient in practical applications, the mutual position and spatial resolution of the parts involved are arbitrarily defined by a human specialist and the final choice of the optimal scales and parts is based on heuristics. This work seeks to understand whether a multi-scale model can take inspiration from human fixations to select specific areas and spatial scales. In more detail, it shows that a multi-scale pyramid representation can be adopted to extract interesting points, and that human attention can be used to select the points at the scales that lead to the best face detection performance. Human fixations can therefore provide a valid methodological basis on which to build a multiscale model, by selecting the spatial scales and areas of interest that are most relevant to humans.

Visual judgments of kinship: an alternative perspective.

Following other researchers, we investigated the premise that visual judgment of kinship might be modelled as a signal-detection task, strictly related to similar facial features. We measured subjects' response times to face-pair stimuli while they performed visual judgments of kinship, similarity, or dissimilarity, and examined some priming effects involved. Our results show that kinship judgment takes longer on average than either similarity or dissimilarity judgment-which is compatible with existing models, yet might also suggest that kinship judgments are of a more complex character. In our priming study we observed selective suppression/enhancement of the efficacy of dissimilarity judgments whenever they followed similarity and kinship judgments. This finding confounds the notion, inherent in previous models, of resemblance cues signalling for kinship, since similarity and dissimilarity cannot be considered just as opposite concepts, and observed priming effects need to be explicitly modelled, including dissimilarity cues. To model kinship judgments across faces that are perceived as dissimilar, a new framework may be required, perhaps accepting the perspective of a task-driven use of the visual cues, modulated by experience and cultural conditioning.