An image processing apparatus includes a representative color calculation unit, a color displacement calculation unit, and a similarity calculation unit. The representative color calculation unit calculates a representative color which is representative of colors in a first region having a predetermined size in an image. The color displacement calculation unit calculates, as a color displacement, a difference between the representative color calculated by the representative color calculation unit and a color in a target second region in the first region. The similarity calculation unit calculates similarity between the color displacement calculated by the color displacement calculation unit and a predetermined color displacement in an information image representing information embedded in the image.