A biometric information processing apparatus comprising: a biometric information acquiring unit which acquires a user's biometric information and generates a biometric input image representing the biometric information; and a processing unit which implements: a first intermediate image generating function which generates a first intermediate image by applying first image processing to the biometric input image; a second intermediate image generating function which generates a second intermediate image by applying second image processing to the biometric input image, the second image processing being different from the first image processing; a singular point candidate detecting function which detects, from each of the first and second intermediate images, a singular point candidate that is a point corresponding to a singular point characterizing biometric input information acquired as the user's biometric information represented by the biometric input image; a singular point candidate distance calculating function which calculates a distance between the singular point candidate detected from the first intermediate image and the singular point candidate detected from the second intermediate image for the same singular point contained in the biometric input information; a quality judging function which calculates a quality metric for the biometric input image in such a manner as to set the quality metric higher as the distance between the singular point candidates decreases, and which judges whether or not the quality metric is higher than a predefined threshold value; and a guidance function which, if the quality metric is not higher than the threshold value, prompts the user to have the user's biometric information reacquired by the biometric information acquiring unit, wherein the first image processing is contrast correction or frequency enhancement, and the second image processing is noise elimination. a biometric information acquiring unit which acquires a user's biometric information and generates a biometric input image representing the biometric information; and a processing unit which implements: a first intermediate image generating function which generates a first intermediate image by applying first image processing to the biometric input image; a second intermediate image generating function which generates a second intermediate image by applying second image processing to the biometric input image, the second image processing being different from the first image processing; a singular point candidate detecting function which detects, from each of the first and second intermediate images, a singular point candidate that is a point corresponding to a singular point characterizing biometric input information acquired as the user's biometric information represented by the biometric input image; a singular point candidate distance calculating function which calculates a distance between the singular point candidate detected from the first intermediate image and the singular point candidate detected from the second intermediate image for the same singular point contained in the biometric input information; a quality judging function which calculates a quality metric for the biometric input image in such a manner as to set the quality metric higher as the distance between the singular point candidates decreases, and which judges whether or not the quality metric is higher than a predefined threshold value; and a guidance function which, if the quality metric is not higher than the threshold value, prompts the user to have the user's biometric information reacquired by the biometric information acquiring unit, wherein the first image processing is contrast correction or frequency enhancement, and the second image processing is noise elimination. a first intermediate image generating function which generates a first intermediate image by applying first image processing to the biometric input image; a second intermediate image generating function which generates a second intermediate image by applying second image processing to the biometric input image, the second image processing being different from the first image processing; a singular point candidate detecting function which detects, from each of the first and second intermediate images, a singular point candidate that is a point corresponding to a singular point characterizing biometric input information acquired as the user's biometric information represented by the biometric input image; a singular point candidate distance calculating function which calculates a distance between the singular point candidate detected from the first intermediate image and the singular point candidate detected from the second intermediate image for the same singular point contained in the biometric input information; a quality judging function which calculates a quality metric for the biometric input image in such a manner as to set the quality metric higher as the distance between the singular point candidates decreases, and which judges whether or not the quality metric is higher than a predefined threshold value; and a guidance function which, if the quality metric is not higher than the threshold value, prompts the user to have the user's biometric information reacquired by the biometric information acquiring unit, wherein the first image processing is contrast correction or frequency enhancement, and the second image processing is noise elimination.