Patent ID: 8593539
Filing Date: 2013-11-26
Classification: H04N

Abstract:
1. An image processing apparatus which performs white balance processing for a moving image obtained by capturing, by an image sensor, an object image formed by an imaging optical system including a stop mechanism capable of changing an aperture value, the apparatus comprising: a storage unit which stores white-detection area information available in correspondence with at least two aperture values; a determination unit which determines an aperture value; a calculation unit which calculates a first white balance coefficient using a frame image obtained using the aperture value determined by said determination unit and a first white-detection area obtained from the white-detection area information in said storage unit in correspondence with the determined aperture value; an estimating unit which calculates a correction amount using the first white detection area and a second white-detection area different from the first white-detection area, and corrects the first white balance coefficient using the calculated correction amount to calculate an estimated white balance coefficient; an application unit which applies a white balance coefficient to a frame image contained in the moving image; and a control unit which, when an aperture value determined by the determination unit changes, controls said application unit to apply the estimated white balance coefficient calculated by said estimating unit to a frame image contained in the moving image, and then apply the first white balance coefficient calculated by said calculation unit to a frame image contained in the moving image, wherein said storage unit stores gravity center positions in a chromaticity space of white-detection areas corresponding to the at least two aperture values as the white-detection area information, and said estimating unit calculates a motion vector between a gravity center position of a white-detection area corresponding to an aperture value before the change and a gravity center position of a white-detection area corresponding to an aperture value after the change, and corrects a current white balance coefficient based on moving amounts of the gravity center position in a color temperature direction and a magenta-green direction to calculate the estimated white balance coefficient.