Imaging device and imaging method

A stereoscopic imaging device, comprising:

• an imaging unit performing, by using an imaging element, optoelectronic conversion of a subject image formed via each of a reference optical system and a separate non-reference optical system, and outputting a plurality of viewpoint images with parallaxes different from each other;
• a reference focusing evaluation area defining unit defining a reference focusing evaluation area corresponding to one of the viewpoint images which is from the reference optical system;
• a subject information determination unit determining subject information about whether a distance from the imaging unit to a subject in the reference focusing evaluation area is long or short;
• a focusing control unit detecting peak positions each of which is a focus position having a local maximum contrast in the reference focusing evaluation area defined by the reference focusing evaluation area defining unit in the viewpoint image from the reference optical system while changing the focus position of the reference optical system, determining an in-focus position corresponding to the subject among the peak positions based on the subject information determined by the subject information determination unit, and moving the focus position of the reference optical system to the determined in-focus position:
• a feature point extraction area defining unit defining a feature point extraction area corresponding to the viewpoint image from the reference optical system, which has the focus position moved to the in-focus position, based on the reference focusing evaluation area;
• a feature point extraction unit extracting a feature point from the feature point extraction area defined in the viewpoint image of the reference optical system by the feature point extraction area defining unit;
• a corresponding point extraction unit extracting a corresponding point corresponding to the feature point, which is extracted by the feature point extraction unit, from the other of the viewpoint images which is froth the non-reference optical system;
• a parallax amount calculation unit calculating an amount of parallax for each pair of the feature point extracted by the feature point extraction unit and the corresponding point extracted by the corresponding point extraction unit;
• a histogram generation unit generating a histogram, which shows distribution of the amount of parallax for each pair, based on the amount of parallax for each pair of the feature point and the corresponding point which is calculated by the parallax amount calculation unit;
• a determining unit determining a significant class, which is a class having the amount of parallax corresponding to the subject, based on the subject information determined by the subject information determination unit and a frequency in the histogram generated by the histogram generation unit;
• and
• a representative parallax amount determination unit determining an amount of representative parallax based on the significant class determined by the determining unit.