Evaluation of Perceived Distortions in Stereoscopic Images

Stereoscopic techniques in medicine are most commonly employed with projection radiography when an appreciation of 3-D structure is desired but not otherwise obtainable using regular x-ray projections. However, analysis of the imaged object may be complicated by distortions in its perceived shape which arise when the images are acquired and viewed using different geometries. The effects of several imaging parameters on the perceived shape of a test pattern were studied geometrically. The distortions are clearly demonstrated, allowing their severity to be assessed and quantified. Additional results are presented which provide an estimate of the smallest resolvable depth that may be measured from a digitized stereo-pair acquired using either of two different approaches.