1998 年 54 巻 4 号 p. 492-498
Observer performance tests were conducted to establish the effects of the noise and film contrast of screen-film systems on the detection of low-contrast signals. Three screen-film systems with different noise levels and film contrast were used in the experiments. The observer performance tests were carried out by the contrast-detail(C-D) diagram method and receiver operating characteristic(ROC) analysis. The results of observer performance tests with the C-D diagram method and ROC analysis indicated that the screen-film system with low noise level and high film contrast provided higher detectability than the system with low noise and low contrast. The screen-film system with high contrast showed greater improvement in detectability than the system with low contrast and low noise at low optical densities, despite the increase in noise.