A digital image capturing and processing system for installation at a retail POS environment comprising a system housing having an imaging window; and a plurality of coplanar illumination and imaging subsystems for projecting a plurality of coplanar illumination and imaging planes through a 3D imaging volume defined relative to the imaging window, for digital imaging of objects passing through the 3D imaging volume. A globally-deployed object motion detection subsystem automatically detects and analyzes the motion of an object passing through at least a portion of the 3D imaging volume, and generates object motion data in response thereto. Object motion data, including object velocity data, is used to generate control data for controlling the operation of the coplanar illumination and imaging subsystems.