/// <summary> /// Computes the center moments for the specified image. /// </summary> /// /// <param name="image">The image whose moments should be computed.</param> /// <param name="area">The region of interest in the image to compute moments for.</param> /// public override void Compute(float[,] image, Rectangle area) { RawMoments raw = new RawMoments(image, area, Order); CentralMoments center = new CentralMoments(raw); this.Compute(center); }
/// <summary> /// Computes the Hu moments from the specified central moments. /// </summary> /// /// <param name="moments">The central moments to use as base of calculations.</param> /// public void Compute(CentralMoments moments) { double inv = 1.0 / moments.Mu00; double inv2 = 1.0 / (moments.Mu00 * moments.Mu00); double inv5d2 = Math.Sqrt(inv2 * inv2 * inv); float n20 = (float)(moments.Mu20 * inv2); float n02 = (float)(moments.Mu02 * inv2); float n11 = (float)(moments.Mu11 * inv2); float n21 = (float)(moments.Mu21 * inv5d2); float n12 = (float)(moments.Mu12 * inv5d2); float n30 = (float)(moments.Mu30 * inv5d2); float n03 = (float)(moments.Mu03 * inv5d2); // (η20 + η02) I1 = (n20 + n02); // (η20 − η02)² + 4 η11² I2 = (n20 - n02) * (n20 - n02) + 4 * (n11 * n11); // (η30 − 3 η12)² I3 = (n30 - 3 * n12) * (n30 - 3 * n12) // + (3 η21 − η03)² + (3 * n21 - n03) * (3 * n21 - n03); // (η30 + η12)² + (η21 + η03)² I4 = (n30 + n12) * (n30 + n12) + (n21 + n03) * (n21 + n03); // (η30 − 3 η12) (η30 + η12) [(η30 + η12)² −3 (η21 + η03)² ] I5 = (n30 - 3 * n12) * (n30 + n12) * ((n30 + n12) * (n30 + n12) - 3 * (n21 + n03) * (n21 + n03)) // (3 η21 − η03) (η21 + η03) [3 (η30 + η12)² − (η21 + η03)² ] + (3 * n21 - n03) * (n21 + n03) * (3 * (n30 + n12) * (n30 + n12) - (n21 + n03) * (n21 + n03)); // (η20 − η02) [(η30 + η12)² − (η21 + η03)² ] I6 = (n20 - n02) * ((n30 + n12) * (n30 + n12) - (n21 + n03) * (n21 + n03)) // + 4 η11 (η30 + η12) (η21 + η03) + 4 * n11 * (n30 + n12) * (n21 + n03); // (3 η21 − η03) (η30 + η12) [(η30 + η12)² − 3 (η21 + η03)² ] I7 = (3 * n21 - n03) * (n30 + n12) * (n30 + n12) * ((n30 + n12) * (n30 + n12) - 3 * (n21 + n03) * (n21 + n03)) // - (η30 − 3 η12) (η21 + η03) [3 (η30 + η12)² − (η21 + η03)² ] - (n30 - 3 * n12) * (n21 + n03) * (3 * (n30 + n12) * (n30 + n12) - (n21 + n03) * (n21 + n03)); }