INTRODUCTION

The proposed volumetric “life-like” 3D image display technique relies upon a display media that is a true 3D volume instead of a 2D flat screen. Each volume element (called “voxel,” analogous to a pixel in a 2D image) in the displayed 3D images locates physically at the (x, y, z ) spatial position where it is supposed to be and emits light from that position to form real 3D images in the eyes of viewers. The volumetric 3D display we developed is fundamentally different from conventional 3D rendering visualization technique, where the object is displayed on a 2D flat screen with 3D rendering for depth perception. It is also different from 3D stereo video or head-mounted display (HMD), where the 3D perception is created with a pair of polarized glasses or display screens.

                            The volumetric 3D display technology projects 3D images directly into true 3D space that does not require special 3D glasses to view it. Viewers can walk around the 3D image and look at it from all different directions with realistic depth just as looking at the real physical object. Such 3D display provides both physiological and psychological depth cues to human viewers for truthfully perceiving objects in 3D space.

                            Furthermore, with realistic 3D representations of medical images in many imaging modalities (CT, MRI, PET, Ultrasound, etc), viewers can interact with the life-sized volumetric 3D images being displayed, via handheld pointer and/or other user–interface devices, as if the true 3D virtual patient were there with a transparent skin and visible internal anatomic structures. The unique capabilities of walk-around viewing and

direct interaction with the displayed 3D images could greatly simplify our understanding of the complexity of 3D objects and spatial relationship among them.

                            We have recently made an important technical breakthrough in implementing the high-resolution volumetric 3D display. Using the spatial light modulator (SLM), high power visible lasers and precision fabrication of helical screen,

we have achieved a multi-color, large display volume, true lifelike 3D display system with a high resolution of over 10 million voxels in a portable design. We have demonstrated our high-resolution volumetric 3D display concept by building a full-scale prototype that can display complex 3D images.