1. A digital image processing device, comprising: an optoelectronic system; a memory; two or more image processing units; wherein the optoelectronic system acquires a plurality of digital images; wherein a first image processing unit of the two or more image processing units: determines, for a first digital image of the plurality of digital images, a location and a boundary of one or more spatial regions where one can expect to detect a face; stores in the memory the first digital image and information about the location and the boundary of one or more spatial regions; processes a second digital image of the plurality of digital images; wherein, as the first image processing unit processes the second digital image, a second image processing unit of the two or more image processing units: retrieves from the memory the location and the boundary of one or more spatial regions; and based on the location and the boundary, retrieves the one or more spatial regions of the first digital image and performs an additional processing on the one or more spatial regions.