Pre-attentive detection of perceptually important regions in facial images

The cascade method, a way of calculating orientation components in an image, was developed to extract some important regions from a given image of a human face. By combining local orientation components and thresholding them, we construct five feature maps and a final composite map which is a linear combination of the five maps. As in human visual perception, the composite map operates like pre-attentive processing in the early stage of vision, and then shows robustness in selecting the most informative areas of images. For 50 non-normalized face images from the ORL database, it showed 91% detection accuracy which is the ratio of corresponding points between the feature maps of a whole image and the same maps of important regions in that image such as eyes, nose and mouth, etc