Method and apparatus for automatically correcting subtraction image desity

摘要: In a temporal subtraction processing conducted by use of stimulable phosphor sheets, the difference between maximum transmitting radiation amount digital image signals detected from sheets carrying images stored therein is calculated. The added to signal obtained prior gradation processing, or conversion table shifted towards high density side along input coordinate axis. Or, read-out conditions in final are adjusted so that eliminated. frequency point calculated histogram signal, representing standard background and calculated, correction made becomes always same.