| 摘要 |
PURPOSE:To express the fine contrast of a radiographic image and to reproduce the radiographic image of an object with high contrast by eliminating a signal component due to the scattered radiation of a read picture signal before allowing the read picture signal to pass an expander and an A/D converter. CONSTITUTION:A signal component Sp bearing the energy of a main transmitted radiation 6a and a signal component Ss bearing the energy of a scattered radiation 6b are superposed on a read picture signal S. A scattered radiation dose forecasting device 24 forecasts a proportion F of the scattered radiation dose to the overall radiation dose irradiated to a storage type phosphor sheet 10 at the radiographing time and inputs this proportion F to an operating circuit 18. The operating circuit 18 receives this signal and multiplies an average signal level Sm by (1-F). It is considered that the scattered radiation is distributed uniformly in the picture, and only the main transmission component is obtained in the operating circuit 18. A picture signal Sp obtained in this manner is inputted to an expander 19. Since the picture signal Sp where the component Ss is eliminated is processed by the expander 19, the contrast is restored by this processing. The signal is digitized by an A/D converter 21 thereafter. |
