1. An omni-directional digital image capturing and processing system for use in a POS environment, comprising: a system housing having horizontal and vertical housing sections; wherein said horizontal housing section has a horizontal imaging window, and contains a first plurality of coplanar illumination and imaging stations, for generating and projecting a first group of coplanar illumination and imaging planes through said horizontal imaging window; a vertical housing section has a vertical imaging window, and contains a second plurality of coplanar illumination and imaging stations for generating and projecting second group of coplanar illumination and imaging planes through said vertical imaging window, which intersects with said first complex of coplanar illumination and imaging planes within a 3D imaging volume definable relative to said horizontal and vertical imaging windows, so as to generate a complex of coplanar illumination and imaging planes within said 3D imaging volume, capable of omni-directional imaging of each object passing through said 3D imaging volume, and generating digital linear images of said object as said object intersects coplanar illumination and imaging planes within said 3D imaging volume during system operation; and wherein each said coplanar illumination and imaging station includes (i) an illumination subsystem having a linear illumination array including a plurality of light emitting devices for producing a planar illumination beam (PLIB), and (ii) an image formation and detection subsystem including a linear image detection array having optics providing a field of view (FOV) on said linear image detection array, and extending substantially along said PLIB so as to form one said coplanar illumination and imaging plane (PLIB/FOV) that is projected through said imaging window and into said 3D imaging volume, for capturing linear digital images of objects moving through said 3D imaging volume, and subsequent processing to read information graphically represented in said linear digital images; (iii) an automatic illumination control subsystem for controlling the production of illumination by said illumination subsystem into said 3D imaging volume, as said objects are detected moving within said 3D imaging volume; and (iv) an image capturing and buffering subsystem for capturing and buffering linear digital images from said linear image detection array.