| /* |
| * Copyright (c) 2016, Alliance for Open Media. All rights reserved |
| * |
| * This source code is subject to the terms of the BSD 2 Clause License and |
| * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License |
| * was not distributed with this source code in the LICENSE file, you can |
| * obtain it at www.aomedia.org/license/software. If the Alliance for Open |
| * Media Patent License 1.0 was not distributed with this source code in the |
| * PATENTS file, you can obtain it at www.aomedia.org/license/patent. |
| */ |
| #define _POSIX_C_SOURCE 200112L // rand_r() |
| #include <memory.h> |
| #include <math.h> |
| #include <time.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <assert.h> |
| |
| #include "av1/encoder/ransac.h" |
| |
| #define MAX_MINPTS 4 |
| #define MAX_DEGENERATE_ITER 10 |
| #define MINPTS_MULTIPLIER 5 |
| |
| #define INLIER_THRESHOLD 1.0 |
| #define MIN_TRIALS 20 |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // ransac |
| typedef int (*IsDegenerateFunc)(double *p); |
| typedef void (*NormalizeFunc)(double *p, int np, double *T); |
| typedef void (*DenormalizeFunc)(double *params, double *T1, double *T2); |
| typedef int (*FindTransformationFunc)(int points, double *points1, |
| double *points2, double *params); |
| typedef void (*ProjectPointsDoubleFunc)(double *mat, double *points, |
| double *proj, const int n, |
| const int stride_points, |
| const int stride_proj); |
| |
| static void project_points_double_translation(double *mat, double *points, |
| double *proj, const int n, |
| const int stride_points, |
| const int stride_proj) { |
| int i; |
| for (i = 0; i < n; ++i) { |
| const double x = *(points++), y = *(points++); |
| *(proj++) = x + mat[0]; |
| *(proj++) = y + mat[1]; |
| points += stride_points - 2; |
| proj += stride_proj - 2; |
| } |
| } |
| |
| static void project_points_double_rotzoom(double *mat, double *points, |
| double *proj, const int n, |
| const int stride_points, |
| const int stride_proj) { |
| int i; |
| for (i = 0; i < n; ++i) { |
| const double x = *(points++), y = *(points++); |
| *(proj++) = mat[2] * x + mat[3] * y + mat[0]; |
| *(proj++) = -mat[3] * x + mat[2] * y + mat[1]; |
| points += stride_points - 2; |
| proj += stride_proj - 2; |
| } |
| } |
| |
| static void project_points_double_affine(double *mat, double *points, |
| double *proj, const int n, |
| const int stride_points, |
| const int stride_proj) { |
| int i; |
| for (i = 0; i < n; ++i) { |
| const double x = *(points++), y = *(points++); |
| *(proj++) = mat[2] * x + mat[3] * y + mat[0]; |
| *(proj++) = mat[4] * x + mat[5] * y + mat[1]; |
| points += stride_points - 2; |
| proj += stride_proj - 2; |
| } |
| } |
| |
| static void project_points_double_hortrapezoid(double *mat, double *points, |
| double *proj, const int n, |
| const int stride_points, |
| const int stride_proj) { |
| int i; |
| double x, y, Z, Z_inv; |
| for (i = 0; i < n; ++i) { |
| x = *(points++), y = *(points++); |
| Z_inv = mat[7] * y + 1; |
| assert(fabs(Z_inv) > 0.000001); |
| Z = 1. / Z_inv; |
| *(proj++) = (mat[2] * x + mat[3] * y + mat[0]) * Z; |
| *(proj++) = (mat[5] * y + mat[1]) * Z; |
| points += stride_points - 2; |
| proj += stride_proj - 2; |
| } |
| } |
| |
| static void project_points_double_vertrapezoid(double *mat, double *points, |
| double *proj, const int n, |
| const int stride_points, |
| const int stride_proj) { |
| int i; |
| double x, y, Z, Z_inv; |
| for (i = 0; i < n; ++i) { |
| x = *(points++), y = *(points++); |
| Z_inv = mat[6] * x + 1; |
| assert(fabs(Z_inv) > 0.000001); |
| Z = 1. / Z_inv; |
| *(proj++) = (mat[2] * x + mat[0]) * Z; |
| *(proj++) = (mat[4] * x + mat[5] * y + mat[1]) * Z; |
| points += stride_points - 2; |
| proj += stride_proj - 2; |
| } |
| } |
| |
| static void project_points_double_homography(double *mat, double *points, |
| double *proj, const int n, |
| const int stride_points, |
| const int stride_proj) { |
| int i; |
| double x, y, Z, Z_inv; |
| for (i = 0; i < n; ++i) { |
| x = *(points++), y = *(points++); |
| Z_inv = mat[6] * x + mat[7] * y + 1; |
| assert(fabs(Z_inv) > 0.000001); |
| Z = 1. / Z_inv; |
| *(proj++) = (mat[2] * x + mat[3] * y + mat[0]) * Z; |
| *(proj++) = (mat[4] * x + mat[5] * y + mat[1]) * Z; |
| points += stride_points - 2; |
| proj += stride_proj - 2; |
| } |
| } |
| |
| static int get_rand_indices(int npoints, int minpts, int *indices, |
| unsigned int *seed) { |
| int i, j; |
| int ptr = rand_r(seed) % npoints; |
| if (minpts > npoints) return 0; |
| indices[0] = ptr; |
| ptr = (ptr == npoints - 1 ? 0 : ptr + 1); |
| i = 1; |
| while (i < minpts) { |
| int index = rand_r(seed) % npoints; |
| while (index) { |
| ptr = (ptr == npoints - 1 ? 0 : ptr + 1); |
| for (j = 0; j < i; ++j) { |
| if (indices[j] == ptr) break; |
| } |
| if (j == i) index--; |
| } |
| indices[i++] = ptr; |
| } |
| return 1; |
| } |
| |
| static int ransac(int *matched_points, int npoints, int *number_of_inliers, |
| double *best_params, const int minpts, |
| IsDegenerateFunc is_degenerate, |
| FindTransformationFunc find_transformation, |
| ProjectPointsDoubleFunc projectpoints) { |
| static const double PROBABILITY_REQUIRED = 0.9; |
| static const double EPS = 1e-12; |
| |
| int N = 10000, trial_count = 0; |
| int i; |
| int ret_val = 0; |
| unsigned int seed = (unsigned int)npoints; |
| |
| int max_inliers = 0; |
| double best_variance = 0.0; |
| double params[MAX_PARAMDIM]; |
| WarpedMotionParams wm; |
| double points1[2 * MAX_MINPTS]; |
| double points2[2 * MAX_MINPTS]; |
| int indices[MAX_MINPTS] = { 0 }; |
| |
| double *best_inlier_set1; |
| double *best_inlier_set2; |
| double *inlier_set1; |
| double *inlier_set2; |
| double *corners1; |
| double *corners2; |
| double *image1_coord; |
| |
| double *cnp1, *cnp2; |
| |
| *number_of_inliers = 0; |
| if (npoints < minpts * MINPTS_MULTIPLIER || npoints == 0) { |
| return 1; |
| } |
| |
| memset(&wm, 0, sizeof(wm)); |
| best_inlier_set1 = |
| (double *)aom_malloc(sizeof(*best_inlier_set1) * npoints * 2); |
| best_inlier_set2 = |
| (double *)aom_malloc(sizeof(*best_inlier_set2) * npoints * 2); |
| inlier_set1 = (double *)aom_malloc(sizeof(*inlier_set1) * npoints * 2); |
| inlier_set2 = (double *)aom_malloc(sizeof(*inlier_set2) * npoints * 2); |
| corners1 = (double *)aom_malloc(sizeof(*corners1) * npoints * 2); |
| corners2 = (double *)aom_malloc(sizeof(*corners2) * npoints * 2); |
| image1_coord = (double *)aom_malloc(sizeof(*image1_coord) * npoints * 2); |
| |
| if (!(best_inlier_set1 && best_inlier_set2 && inlier_set1 && inlier_set2 && |
| corners1 && corners2 && image1_coord)) { |
| ret_val = 1; |
| goto finish_ransac; |
| } |
| |
| for (cnp1 = corners1, cnp2 = corners2, i = 0; i < npoints; ++i) { |
| *(cnp1++) = *(matched_points++); |
| *(cnp1++) = *(matched_points++); |
| *(cnp2++) = *(matched_points++); |
| *(cnp2++) = *(matched_points++); |
| } |
| matched_points -= 4 * npoints; |
| |
| while (N > trial_count) { |
| int num_inliers = 0; |
| double sum_distance = 0.0; |
| double sum_distance_squared = 0.0; |
| |
| int degenerate = 1; |
| int num_degenerate_iter = 0; |
| while (degenerate) { |
| num_degenerate_iter++; |
| if (!get_rand_indices(npoints, minpts, indices, &seed)) { |
| ret_val = 1; |
| goto finish_ransac; |
| } |
| i = 0; |
| while (i < minpts) { |
| int index = indices[i]; |
| // add to list |
| points1[i * 2] = corners1[index * 2]; |
| points1[i * 2 + 1] = corners1[index * 2 + 1]; |
| points2[i * 2] = corners2[index * 2]; |
| points2[i * 2 + 1] = corners2[index * 2 + 1]; |
| i++; |
| } |
| degenerate = is_degenerate(points1); |
| if (num_degenerate_iter > MAX_DEGENERATE_ITER) { |
| ret_val = 1; |
| goto finish_ransac; |
| } |
| } |
| |
| if (find_transformation(minpts, points1, points2, params)) { |
| trial_count++; |
| continue; |
| } |
| |
| projectpoints(params, corners1, image1_coord, npoints, 2, 2); |
| |
| for (i = 0; i < npoints; ++i) { |
| double dx = image1_coord[i * 2] - corners2[i * 2]; |
| double dy = image1_coord[i * 2 + 1] - corners2[i * 2 + 1]; |
| double distance = sqrt(dx * dx + dy * dy); |
| |
| if (distance < INLIER_THRESHOLD) { |
| inlier_set1[num_inliers * 2] = corners1[i * 2]; |
| inlier_set1[num_inliers * 2 + 1] = corners1[i * 2 + 1]; |
| inlier_set2[num_inliers * 2] = corners2[i * 2]; |
| inlier_set2[num_inliers * 2 + 1] = corners2[i * 2 + 1]; |
| num_inliers++; |
| sum_distance += distance; |
| sum_distance_squared += distance * distance; |
| } |
| } |
| |
| if (num_inliers >= max_inliers && num_inliers > 1) { |
| int temp; |
| double fracinliers, pNoOutliers, mean_distance, variance; |
| |
| mean_distance = sum_distance / ((double)num_inliers); |
| variance = sum_distance_squared / ((double)num_inliers - 1.0) - |
| mean_distance * mean_distance * ((double)num_inliers) / |
| ((double)num_inliers - 1.0); |
| if ((num_inliers > max_inliers) || |
| (num_inliers == max_inliers && variance < best_variance)) { |
| best_variance = variance; |
| max_inliers = num_inliers; |
| // Save parameters, excluding the implicit '1' in the bottom-right |
| // entry of the parameter matrix |
| memcpy(best_params, params, (MAX_PARAMDIM - 1) * sizeof(*best_params)); |
| memcpy(best_inlier_set1, inlier_set1, |
| num_inliers * 2 * sizeof(*best_inlier_set1)); |
| memcpy(best_inlier_set2, inlier_set2, |
| num_inliers * 2 * sizeof(*best_inlier_set2)); |
| |
| assert(npoints > 0); |
| fracinliers = (double)num_inliers / (double)npoints; |
| pNoOutliers = 1 - pow(fracinliers, minpts); |
| pNoOutliers = fmax(EPS, pNoOutliers); |
| pNoOutliers = fmin(1 - EPS, pNoOutliers); |
| temp = (int)(log(1.0 - PROBABILITY_REQUIRED) / log(pNoOutliers)); |
| if (temp > 0 && temp < N) { |
| N = AOMMAX(temp, MIN_TRIALS); |
| } |
| } |
| } |
| trial_count++; |
| } |
| find_transformation(max_inliers, best_inlier_set1, best_inlier_set2, |
| best_params); |
| *number_of_inliers = max_inliers; |
| finish_ransac: |
| aom_free(best_inlier_set1); |
| aom_free(best_inlier_set2); |
| aom_free(inlier_set1); |
| aom_free(inlier_set2); |
| aom_free(corners1); |
| aom_free(corners2); |
| aom_free(image1_coord); |
| return ret_val; |
| } |
| |
| static int is_collinear3(double *p1, double *p2, double *p3) { |
| static const double collinear_eps = 1e-3; |
| const double v = |
| (p2[0] - p1[0]) * (p3[1] - p1[1]) - (p2[1] - p1[1]) * (p3[0] - p1[0]); |
| return fabs(v) < collinear_eps; |
| } |
| |
| static int is_degenerate_translation(double *p) { |
| return (p[0] - p[2]) * (p[0] - p[2]) + (p[1] - p[3]) * (p[1] - p[3]) <= 2; |
| } |
| |
| static int is_degenerate_affine(double *p) { |
| return is_collinear3(p, p + 2, p + 4); |
| } |
| |
| static int is_degenerate_homography(double *p) { |
| return is_collinear3(p, p + 2, p + 4) || is_collinear3(p, p + 2, p + 6) || |
| is_collinear3(p, p + 4, p + 6) || is_collinear3(p + 2, p + 4, p + 6); |
| } |
| |
| int ransac_translation(int *matched_points, int npoints, int *number_of_inliers, |
| double *best_params) { |
| return ransac(matched_points, npoints, number_of_inliers, best_params, 3, |
| is_degenerate_translation, find_translation, |
| project_points_double_translation); |
| } |
| |
| int ransac_rotzoom(int *matched_points, int npoints, int *number_of_inliers, |
| double *best_params) { |
| return ransac(matched_points, npoints, number_of_inliers, best_params, 3, |
| is_degenerate_affine, find_rotzoom, |
| project_points_double_rotzoom); |
| } |
| |
| int ransac_affine(int *matched_points, int npoints, int *number_of_inliers, |
| double *best_params) { |
| return ransac(matched_points, npoints, number_of_inliers, best_params, 3, |
| is_degenerate_affine, find_affine, |
| project_points_double_affine); |
| } |
| |
| int ransac_homography(int *matched_points, int npoints, int *number_of_inliers, |
| double *best_params) { |
| return ransac(matched_points, npoints, number_of_inliers, best_params, 4, |
| is_degenerate_homography, find_homography, |
| project_points_double_homography); |
| } |
| |
| int ransac_hortrapezoid(int *matched_points, int npoints, |
| int *number_of_inliers, double *best_params) { |
| return ransac(matched_points, npoints, number_of_inliers, best_params, 4, |
| is_degenerate_homography, find_hortrapezoid, |
| project_points_double_hortrapezoid); |
| } |
| |
| int ransac_vertrapezoid(int *matched_points, int npoints, |
| int *number_of_inliers, double *best_params) { |
| return ransac(matched_points, npoints, number_of_inliers, best_params, 4, |
| is_degenerate_homography, find_vertrapezoid, |
| project_points_double_vertrapezoid); |
| } |
