Improvements to weighted tracks behavior

First thing changed by this commit is making it so
Euclidean intersection takes track weight into account
when solving minimization problem. This behaves the
same exact way as it is for BA step.

Second thing is related on how average reprojection error
is being calculated. It didn't take track weight into
account which could confuse users. Now average reprojection
error will give the same result as intersection/BA uses
during minimization which gives much more predictable
behavior.

Differential Revision: https://developer.blender.org/D265

extern/libmv/ChangeLog

@@ -1,8 +1,34 @@
-commit f71f7c59d4d13574ea4dc3a196cc22eef1c192df
+commit cd7eb3eff2e69ce5e08570ead83ae6d35ee48857
+Author: Sergey Sharybin <sergey.vfx@gmail.com>
+Date:   Tue Jan 28 17:23:47 2014 +0600
+
+    Improvements to weighted tracks behavior
+    
+    First thing changed by this commit is making it so
+    Euclidean intersection takes track weight into account
+    when solving minimization problem. This behaves the
+    same exact way as it is for BA step.
+    
+    Second thing is related on how average reprojection error
+    is being calculated. It didn't take track weight into
+    account which could confuse users. Now average reprojection
+    error will give the same result as intersection/BA uses
+    during minimization which gives much more predictable
+    behavior.
+    
+    Reviewers: keir
+    
+    Reviewed By: keir
+    
+    CC: sebastian_k
+    
+    Differential Revision: https://developer.blender.org/D265
+
+commit 6559b36dc14369175bfa0830323146acd3426483
 Author: Sergey Sharybin <sergey.vfx@gmail.com>
 Date:   Tue Jan 28 16:39:14 2014 +0600
 
-    Fixed for keyframe selection
+    Fixes for keyframe selection
     
     Using tracks with constant zero weight used to crash
     keyframe selection since it was trying to use missing
@@ -660,17 +686,3 @@ Date:   Sat Apr 6 18:37:37 2013 +0600
     It is failing at this moment and this is caused because
     of how SampleLinear works - seems it's assumption about
     pixel center is not correct for internal sampling.
-
-commit d449b820fb3352cd981e06d737f2838adb3d36bd
-Author: Sergey Sharybin <sergey.vfx@gmail.com>
-Date:   Sat Apr 6 16:54:08 2013 +0600
-
-    Tweak to KLT region tracker test
-    
-    KLT is usually used to track relatively small
-    motions, and in this case motion almost equals
-    to half window size. This confuses math and
-    leads to not so much expected result.
-    
-    Further, not actually sure this is nice idea
-    to use KLT in such synthetic case.

extern/libmv/libmv/simple_pipeline/intersect.cc

@@ -54,8 +54,8 @@ class EuclideanIntersectCostFunctor {
     Vec3 projected = R * x + t;
     projected /= projected(2);
 
-    residuals[0] = projected(0) - T(marker_.x);
-    residuals[1] = projected(1) - T(marker_.y);
+    residuals[0] = (projected(0) - T(marker_.x)) * marker_.weight;
+    residuals[1] = (projected(1) - T(marker_.y)) * marker_.weight;
 
     return true;
   }
@@ -102,16 +102,18 @@ bool EuclideanIntersect(const vector<Marker> &markers,
 
   for (int i = 0; i < markers.size(); ++i) {
     const Marker &marker = markers[i];
-    const EuclideanCamera &camera =
-        *reconstruction->CameraForImage(marker.image);
+    if (marker.weight != 0.0) {
+      const EuclideanCamera &camera =
+          *reconstruction->CameraForImage(marker.image);
 
-    problem.AddResidualBlock(
-        new ceres::AutoDiffCostFunction<
-            EuclideanIntersectCostFunctor,
-            2, /* num_residuals */
-            3>(new EuclideanIntersectCostFunctor(marker, camera)),
-        NULL,
-        &X(0));
+      problem.AddResidualBlock(
+          new ceres::AutoDiffCostFunction<
+              EuclideanIntersectCostFunctor,
+              2, /* num_residuals */
+              3>(new EuclideanIntersectCostFunctor(marker, camera)),
+          NULL,
+          &X(0));
+    }
   }
 
   // Configure the solve.

extern/libmv/libmv/simple_pipeline/pipeline.cc

@@ -277,11 +277,12 @@ double InternalReprojectionError(
   double total_error = 0.0;
   vector<Marker> markers = image_tracks.AllMarkers();
   for (int i = 0; i < markers.size(); ++i) {
+    double weight = markers[i].weight;
     const typename PipelineRoutines::Camera *camera =
         reconstruction.CameraForImage(markers[i].image);
     const typename PipelineRoutines::Point *point =
         reconstruction.PointForTrack(markers[i].track);
-    if (!camera || !point) {
+    if (!camera || !point || weight == 0.0) {
       num_skipped++;
       continue;
     }
@@ -289,8 +290,8 @@ double InternalReprojectionError(
 
     Marker reprojected_marker =
         PipelineRoutines::ProjectMarker(*point, *camera, intrinsics);
-    double ex = reprojected_marker.x - markers[i].x;
-    double ey = reprojected_marker.y - markers[i].y;
+    double ex = (reprojected_marker.x - markers[i].x) * weight;
+    double ey = (reprojected_marker.y - markers[i].y) * weight;
 
     const int N = 100;
     char line[N];