Real-time 'computer-evaded' pseudo-holography of computed tomography images.
An off-line method of dynamic imaging has been developed to facilitate visualization of three-dimensional tomographic data during real-time manoeuvres. Stereo-pair projection of multiple contiguous cross-sectional images on a conventional 625 line 50 Hz television raster has been investigated and pseudo-holograms have been displayed. A Cartesian stereo-pair projection model incorporating three degrees of rotational freedom and perspective has been developed. Computer simulations of the model have been conducted and the feasibility of adopting a simplified model has been examined. A condensed solution with two degrees of freedom, retaining partial perspective effects, has been simulated and analysed for worst-case errors. Reasonable projection accuracy has been demonstrated for small orientation angles. Specialized display hardware has been developed and a departure has been made from conventional picture-element (pixel) display methodology. Elemental quadrilaterals (rho-pixels), varying in size, shape and screen position, have been considered as an alternative to static square pixels in a rigid matrix. Joystick-controlled rho-pixel arrays have been implemented with parallelogram-shaped rho-pixels incorporated as a simplified case of quadrilateral projection. Dynamic stereo-pair projections of 64 X 64 rho-pixel arrays have been generated from computed tomography (CT) images and the results of phantom studies on a four-plane system are discussed.
Department of Electrical and Electronic Engineering, University of Ulster, Jordanstown, Northern Ireland.
J A
JA
Webb
D H
DH
Noblett
D003198:Computer Simulation; D006696:Holography / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D008433:Mathematics; D008838:Microcomputers; D008961:Models, Structural; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*