| 摘要 |
PURPOSE:To obtain an image signal representing a radiation image having got rid of a dust shade, which has eventually been appearing on the radiation image, by determining the image signal representing a peculiar pattern removed image, in which a pattern having appeared peculiarly in one picture with radiation image is either removed or attenuated from that picture with radiation image. CONSTITUTION:Breast 13a of a human body 13 is irradiated with X-rays 12 given from an X-ray source 11 of an X-ray photographing device 10, and penetrative X-ray images are cumulatively recorded on sheets 14, 15. These No.1 and No.2 sheet 14, 15 are set one after another in place in an X-ray image reading device 20, and No.1 and No.2 image signal S1, S2 are entered into a computer system 40. Calculations are made for each set of mutually mating picture elements of No.1 calcification shade stressed image and No.2 calcification shade stressed image, and a difference image signal S3 representing their difference image is obtained. Further, a new difference image signal S3 is determined, and calculations are made for each set of mutually mating picture elements, and a dust removed image is produced which holds the calcification shade 2 as it is and which has got rid of the dust shade 1 solely. |
