Support trapezoidal models for global motion
Adds functinoality for least-squares, RANSAC as well as encoding and
decoding with new constrained homographies that warp blocks to horizontal
and/or vertical trapezoids. This is for future experimentation. None
of the models are actually enabled in the code.
Change-Id: I1936018c6b11587d6fd83c3a2c63548cb641b33f
diff --git a/av1/encoder/ransac.c b/av1/encoder/ransac.c
index 766a1cf..3b06710 100644
--- a/av1/encoder/ransac.c
+++ b/av1/encoder/ransac.c
@@ -22,6 +22,9 @@
#define MAX_DEGENERATE_ITER 10
#define MINPTS_MULTIPLIER 5
+#define INLIER_THRESHOLD 1.0
+#define MIN_TRIALS 20
+
////////////////////////////////////////////////////////////////////////////////
// ransac
typedef int (*IsDegenerateFunc)(double *p);
@@ -76,6 +79,42 @@
}
}
+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,
@@ -121,10 +160,8 @@
IsDegenerateFunc is_degenerate,
FindTransformationFunc find_transformation,
ProjectPointsDoubleFunc projectpoints) {
- static const double inlier_threshold = 1.0;
static const double PROBABILITY_REQUIRED = 0.9;
static const double EPS = 1e-12;
- static const int MIN_TRIALS = 20;
int N = 10000, trial_count = 0;
int i;
@@ -223,7 +260,7 @@
double dy = image1_coord[i * 2 + 1] - corners2[i * 2 + 1];
double distance = sqrt(dx * dx + dy * dy);
- inlier_mask[i] = distance < inlier_threshold;
+ inlier_mask[i] = distance < INLIER_THRESHOLD;
if (inlier_mask[i]) {
inlier_set1[num_inliers * 2] = corners1[i * 2];
inlier_set1[num_inliers * 2 + 1] = corners1[i * 2 + 1];
@@ -332,3 +369,19 @@
best_params, 4, is_degenerate_homography, find_homography,
project_points_double_homography);
}
+
+int ransac_hortrapezoid(int *matched_points, int npoints,
+ int *number_of_inliers, int *best_inlier_mask,
+ double *best_params) {
+ return ransac(matched_points, npoints, number_of_inliers, best_inlier_mask,
+ best_params, 4, is_degenerate_homography, find_hortrapezoid,
+ project_points_double_hortrapezoid);
+}
+
+int ransac_vertrapezoid(int *matched_points, int npoints,
+ int *number_of_inliers, int *best_inlier_mask,
+ double *best_params) {
+ return ransac(matched_points, npoints, number_of_inliers, best_inlier_mask,
+ best_params, 4, is_degenerate_homography, find_vertrapezoid,
+ project_points_double_vertrapezoid);
+}
