Digital image processing: effect on detectability of simulated low-contrast radiographic patterns.

摘要: Detection studies of simulated low-contrast radiographic patterns were performed with a high-quality digital image processing system. The original images, prepared conventional screen-film systems, processed digitally to enhance contrast by "windowing" technique. detectability was quantified in terms the results observer performance experiments using multiple-alternative forced-choice method. images demonstrated significant increase detection over that for images. These are related displayed and perceived signal-to-noise ratios derived from signal theory. improvement is ascribed reduction relative magnitude human observer's "internal" noise after processing. measured dependence threshold on object size level accounted statistical decision theory model includes internal noise.