Patent ID: 9294668
Filing Date: 2016-03-22
CPC Classification: H04N

Claim Text:
1. A ranging apparatus for calculating a defocus amount on the basis of an image shift amount which is a relative position shift amount of first picture image data based on a first light flux passing through a first pupil region of an imaging optical system, and second picture image data based on a second light flux passing through a second pupil region of the imaging optical system, the ranging apparatus comprising: an output ratio data calculation unit configured to calculate a value of a ratio of an output value of a pixel of the first picture image data and an output value of a pixel of the second picture image data at a corresponding pixel position at a plurality of pixel positions, and to calculate output ratio data which are a set of the values of the ratio; a correction function calculation unit configured to calculate a correction function approximating the output ratio data by an N-order function, where N is an integer equal to or greater than 1, having a pixel position as a variable; a correction unit configured to correct at least one of the first picture image data and the second picture image data on the basis of the correction function; and a ranging unit configured to calculate the defocus amount by using the picture image data corrected by the correction unit.