A method for more efficiently detecting faces in images is disclosed. The
integral image of an image may be calculated. The integral image may be
sub-sampled to generate one or more sub-sampled integral images. A
plurality of classifiers may be applied in one or more stages to regions
of each sub-sampled integral image, where the application of the
classifiers may produce classification data. The classification data may
be used to determine if a face is associated with any of the regions of
each sub-sampled integral image. The face determination results may be
used to modify the original image such that, when rendered, the image is
displayed with a graphical object identifying the face in the image.
Accordingly, face detection processing efficiency may be increased by
reducing the number of integral image calculations and processing
localized data through application of classifiers to sub-sampled integral
images.