1. A biological information processor comprising: an area detection unit configured to detect an area in which a person is displayed from image information; a feature extraction unit configured to extract feature information based on a characteristic portion of a person from the area detected by the area detection unit from the image information; and a determination unit configured to determine an extraction precision indicating whether or not the characteristic portion of the person can be extracted, with respect to the feature information extracted by the feature extraction unit based on a position of the characteristic portion.