Abstract: A keyword assignment device includes a class determination section that determines a corresponding class when a plurality of keywords are classified into a plurality of classes that are distributed in first to Nth hierarchies, a classification frequency calculation section that calculates a classification frequency of each class, a reference target hierarchy determination section that determines a reference target hierarchy, and a keyword determination section that determines the keyword of the corresponding class in the final reference target hierarchy to be a display keyword. The reference target hierarchy determination section determines a kth hierarchy to be the next reference target hierarchy when it has been determined that it is necessary to refer to the kth hierarchy that is higher than a jth hierarchy based on the classification frequency of the corresponding class in the jth hierarchy.

Abstract: An image processing apparatus configured to perform face detection on an image signal of an image to be processed, includes a target region setting unit configured to set a target region of a face detection process in the image to be processed, and a characteristic extraction unit configured to extract a characteristic of the image signal of the target region set by the target region setting unit. The image processing apparatus further includes a tone conversion unit configured to perform tone conversion on the image signal of the target region set by the target region setting unit according to the characteristic extracted by the characteristic extraction unit, and a face detection unit configured to detect a face region based on the image signal tone-converted by the tone conversion unit.

Abstract: A face candidate of an object having movable ears is detected by a face candidate detection unit from an image of the object, and an ear of the object is detected by an attached site detection unit. The object is then detected from the image by a head portion determination unit in accordance with the detected face candidate and ear.