A LED-based planar light illumination and imaging (PLIIM) engine for use in a hand-supportable linear imager adapted for manual movement relative to an object to be illuminated and imaged. The LED-based PLIIM engine comprises an engine housing having a light transmission aperture, and a linear image formation and detection (IFD) module having a linear image detection array with image detection elements and image formation optics having a field of view (FOV) projected through the light transmission aperture into an illumination and imaging field, in which an object is presented for illumination and imaging. A pair of planar light illumination arrays (PLIAs) are arranged on opposite sides of the linear IFD module. Each PLIA includes a plurality of planar light illumination modules (PLIMs) for producing a plurality of spatially-incoherent planar light illumination beam (PLIB) components which are spatially aligned to produce a planar light illumination beam (PLIB) arranged in a coplanar relationship with a portion of the FOV. Each PLIM includes a light emitting diode (LED) and beam focusing and diverging optics for producing one PLIB component. An image frame grabber is provided for grabbing images formed and detected by the linear IFD module. An image data buffer is provided for buffering the grabbed linear images. A controller is provided for controlling the linear IFD module, and the pair of planar light illumination arrays. As the engine housing moves past the object, a series of linear images of the object are sequentially detected by the linear IFD module, grabbed by the image frame grabber, and buffered in the image data buffer for subsequent processing by an image processing computer, so to decode a 1-D or 2-D bar code symbol structure represented within the structure of said two-dimensional image, or recognize character strings or other forms of graphical intelligence represented therewithin.