An image processing apparatus that corrects gradation of a first image, which is one image from among the image for left eye and the image for right eye, and gradation of a second image, which is the other image from among the image for left eye and the image for right eye, the image processing apparatus comprises: a detection unit that detects parallax between the first image and second image; a correction unit that detects a pixel in the second image corresponding to a pixel in the first image on the basis of the parallax, and corrects a gradation value of the pixel in the first image and a gradation value of the pixel in the second image corresponding to the pixel in the first image by using a single gradation conversion curve.