A digital still camera for photographing an image of an object is provided. A motion vector detector acquires a change of a position of the object in the image between a first picture frame and a previous picture frame recorded prior thereto. A normalizer normalizes the previous picture frame according to a parameter related to the change of the position. A specific object detector detects a specific object region, such as a facial image region, according to image recognition and by comparison between the first picture frame and the normalized previous picture frame. Furthermore, a change of a magnification of the image thereof is acquired between the first picture frame and the previous picture frame recorded prior thereto. The normalizer normalizes the previous picture frame according to a parameter related to the change of the magnification.