1. A system comprising: (a) a feature-detection circuit configured to extract at least one respective human-perceivable feature included in each medical image of a plurality of medical images of the skin of an individual human (hereafter “medical skin images”), the each medical image of plurality of medical skin images includes a respective portion of a region of interest of a surface of the skin of the individual human, and was acquired by a handheld digital image acquisition device; (b) a feature-matching circuit configured to determine a substantial correspondence between (x) an extracted human-perceivable feature included in a border region segment of a selected medical skin image of the plurality of medical skin images and (y) an extracted at least one respective human-perceivable feature included in the each medical skin image of the plurality of medical skin images other than the selected medical skin image; (c) a data collection circuit configured to gather the determined substantial correspondences for the human-perceivable feature included in the border region segment of the selected medical skin image; and (d) a reporting circuit configured to output informational data indicative of a possible non-imaged portion of the region of interest of the skin of the individual human adjacent to the selected medical skin image, the informational data responsive to an absence of a determined substantial correspondence between the extracted human-perceivable feature included in the border region segment of the selected medical skin image and the extracted at least one respective feature included in the each medical skin image of the plurality of medical skin images other than the selected medical skin image.