Radiation image read-out method

Abstract

In a method of reading out a radiation image stored in a stimulable phosphor sheet, preliminary read-out for approximately detecting the image is conducted. A cumulative histogram of the image information is created, read-out conditions in the final read-out are corrected based on a characteristic value of the cumulative histogram, then the final read-out is conducted using the corrected conditions. Alternatively, a standard image information range is determined from the characteristic value, and the read-out conditions are adjusted so that the standard range corresponds to a predetermined electronic signal range. In addition, in the read-out method where gradation processing is performed for electronic image signals obtained by photoelectrically detecting the phosphor light emitted by the sheet, histogram of the image signals is created, and a desired image signal range is determined therefrom. A cummulative histogram then is created, the desired range is corrected based on a characteristic value of the cumulative histogram, and gradation processing conditions are adjusted so that the corrected desired signal range corresponds to a predetermined electronic signal range. Alternatively, a standard signal range is determined based on the characteristic value, and gradation processing conditions are adjusted so that the standard range corresponds to a predetermined electronic signal range.