Human visual system modeling for selecting the optimal display for digital radiography

Abstract Observer performance studies and receiver operating characteristic (ROC) analysis are useful for determining experimentally the effects of imaging parameters on the diagnostic performance of radiologists. Comprehensive optimization of image acquisition, processing, and display systems for digital radiography based solely on measurements of reader performance is impractical, however, due to the large number of interdependent variables to be tested. Observer models that account for the effects of those variables on the visual perception of images offer potential for expediting the evaluation and optimization of new technologies. We have conducted several studies to evaluate the applicability of a visual discrimination model (VDM), JNDmetrix, for predicting trends in observer performance in detection and discrimination tasks as a function of various image display and processing factors: display function and peak luminance, CRT phosphor noise, MTF compensation, viewing angle (LCD vs. CRT), image compression, and grayscale window enhancements. Our results suggest that the VDM could be useful in the assessment and optimization of new image display and processing technologies for digital radiography.