1. A hand-supportable digital image capture and processing system comprising: a hand-supportable housing; an image formation and detection subsystem, disposed in said hand-supportable housing, and having image formation optics for producing a field of view (FOV) upon an object to be imaged and an area-type image sensing array for detecting imaged light reflected off the object during illumination operations in a single image frame capture mode in which a plurality of rows of sensor elements in said area-type image sensing array are enabled so as to detect a 2D digital image of the object on said area-type image sensing array; an LED-based illumination subsystem, disposed in said hand-supportable housing, and having an LED-based illumination array for producing a field of LED-based illumination within the FOV of said image formation and detection subsystem during said single image frame capture mode; an automatic illumination control subsystem disposed in said hand-supportable housing, for automatically controlling the operation of said LED-based illumination subsystem; an image capturing and buffering subsystem disposed in said hand-supportable housing, for capturing and buffering 2-D digital images detected by said image formation and detection subsystem; an image processing subsystem disposed in said hand-supportable housing, for processing 2-D digital images captured and buffered by said image capturing and buffering subsystem and producing processed image data; and an input/output subsystem disposed in said hand-supportable housing, for outputting processed image data to an external host system or other information receiving or responding device; a system control subsystem disposed in said hand-supportable housing, for activating and controlling said subsystem components described above; wherein according to a global exposure control method carried out under said system control subsystem, when (i) said area-type image sensing array is activated during said single image frame capture mode, and (ii) said plurality of rows of sensor elements in said area-type image sensing array are in a state of integration and have a common integration time, then said automatic illumination control subsystem automatically drives said LED-based illumination array so that said plurality of rows of sensor elements in said area-type image sensing array are simultaneously exposed to LED-based illumination reflected and/or scattered off an object within said FOV, and thereby enabling said area-type image sensing array to detect a high quality digital image of the illuminated object, independent of the relative motion between said object and hand-supportable housing during said single image frame capture mode of operation.