PROBLEM TO BE SOLVED: To provide an image processing apparatus, an image processing method and an image processing program that can normalize an image of a subject by correcting, with a high accuracy, distortion in a three-dimensional shape of the photographed subject.SOLUTION: An image processing apparatus approximates a three-dimensional shape of a subject, acquired from an image of the subject, by a quadric surface, applies a plane expansion process that expands the quadric surface into an expansion plane, to data of the image, computes corresponding points before and after the plane expansion process, and generates normalized data of the image from the corresponding points that are computed. The corresponding points are computed based on a point on a straight line of the expansion plane in contact with a point on the quadric surface and corresponding to a reference point on the subject, and an intersection point of an imaginary straight line, passing through the point on the straight line and extending in a direction of a normal vector with respect to the straight line, and a quadratic curve of the quadric surface.SELECTED DRAWING: Figure 7【課題】画像処理装置、画像処理方法及び画像処理プログラムにおいて、撮影した被写体の３次元形状の歪みを高精度で補正して被写体の画像を正規化することを目的とする。【解決手段】被写体の画像から取得した、前記被写体の３次元形状を２次曲面で近似し、前記画像のデータに、前記２次曲面を展開平面に展開する平面展開処理を適用し、前記平面展開処理の前後の対応点を算出し、算出した前記対応点から、正規化された画像のデータを生成し、前記対応点は、前記被写体の基準点に対応する、前記２次曲面上の点に接する前記展開平面の直線上の点と、前記直線上の前記点を通る、前記直線に対する法線ベクトル方向の仮想直線と前記２次曲面の２次曲線との交点とに基づいて算出する。【選択図】図７
