Translator Disclaimer
28 June 2001 Effect of shift invariance and stationarity assumptions on simple detection tasks: spatial and spatial frequency domains
Author Affiliations +
Abstract
A lens-coupled digital radiography system was used to investigate the impact of shift invariance and stationarity assumptions on task-based measures of performance. Experimental data are available on the imaging system's large area gray-scale transfer (sensitivity), resolution (modulation transfer function) and noise (variance map, autocovariance function, and noise power spectrum) properties in different regions of the field of view. These data were obtained for two different values of optical demagnification factor and three levels of x-ray exposure. Evidence of shift variant and non-stationary behavior is seen in the position dependence of the sensitivity, resolution and noise properties of the imaging system. Estimates of observer performance in terms of signal-to- noise-ratio were obtained from one algorithmic observer (DC- suppressed matched filter) and from one analytic observer (pre-whitening matched filter) for the task of detecting a known object (CDMAM phantom) on a flat background. For the special case of a large object at the center of the field- of-view, estimates of observer performance were essentially the same whether based on spatial or spatial frequency domain measures.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Robert M. Gagne, Kyle J. Myers, and Philip W. Quinn "Effect of shift invariance and stationarity assumptions on simple detection tasks: spatial and spatial frequency domains", Proc. SPIE 4320, Medical Imaging 2001: Physics of Medical Imaging, (28 June 2001); https://doi.org/10.1117/12.430938
PROCEEDINGS
8 PAGES


SHARE
Advertisement
Advertisement
Back to Top