PROBLEM TO BE SOLVED: To provide a mechanism for accurately estimating a normal structure of a layer constituting an object.SOLUTION: An image processing apparatus includes: a layer detection unit 221 for detecting a layer from a tomographic image of a fundus oculi of a subject's eye； and in a detected layer by the layer detection unit 221, a normal structure estimation unit 222 for detecting a plurality of characteristic points including deep points positioned in a deep part than the threshold to the depth direction of the fundus oculi based on the shape of the layer detected by the layer detection unit 221, and obtaining a convex curve in the depth direction of the fundus oculi based on the plurality of characteristic points including the deep points.
