An imaging device includes: an optical system (10) that includes a first pupil (11) that allows light within a first wavelength band to pass through, and a second pupil (13) that allows light within a second wavelength band to pass through, the second wavelength band differing from the first wavelength band; an image sensor (20) that includes a first-color filter that has first transmittance characteristics, a second-color filter that has second transmittance characteristics, and a third-color filter that has third transmittance characteristics, and acquires a pixel value (b) that corresponds to a first color, a pixel value (g) that corresponds to a second color, and a pixel value (r) that corresponds to a third color; a correction processing section (120) that corrects the pixel value (b) that corresponds to the first color and the pixel value (r) that corresponds to the third color based on a component value that corresponds to an overlapping region of the first transmittance characteristics (F B ) and the third transmittance characteristics; and a phase difference detection section (185) that detects the phase difference (´) between an image formed by the corrected pixel value (b) that corresponds to the first color and an image formed by the corrected pixel value (r') that corresponds to the third color.