Provided is an image-processing portion including: a fat-region setting portion that detects fat-region information that indicates a fat region in which fat exists in a biological-tissue image a blood-region-information detecting portion that detects blood-region information that indicates a blood region in which blood exists in the biological-tissue image a confidence-calculating portion that calculates a confidence for the fat-region information on a basis of the fat-region-information detected by the fat-region setting portion and the blood-region-information detected by the blood-region-information detecting portion and a display-form setting portion that manipulates the fat region indicated by the fat-region information for which the calculated confidence calculated by the fat-region confidence-calculating portion is lower than a reference confidence that serves as a reference so as to have a display form that can be distinguished from a peripheral region.
