Image capturing apparatus and focusing method with focus evaluation

Abstract

The image capturing apparatus includes: a taking optical system which includes a focusing lens; an imaging unit which receives a subject light through the taking optical system and converts the subject light to image data representing frame images; a face detection unit which detects a face region of a person in a first frame image that is one of the frame images sequentially supplied by the imaging unit; a face detection setting unit which sets, for the face detection unit, a position and a size of a face region detection area in a second frame image supplied after the first frame image by the imaging unit, in accordance with a position and a size of the face region detected by the face detection unit in the first frame image; a focus region defining unit which defines, in accordance with a position and a size of the face region detected by the face detection unit in the second frame image, a focus evaluation value calculation region in a third frame image supplied after the second frame image by the imaging unit; a calculation unit which calculates a focus evaluation value in accordance with the image data in the focus evaluation value calculation region defined by the focus region defining unit in the third frame image; and a focus adjustment unit which adjusts a focus of the focusing lens in accordance with the focus evaluation value calculated by the calculation unit.