Patch for grabCut asserts in OpenCV 2.3.1

grabcut.patch

*** ../modules/imgproc/src/grabcut.cpp	2011-09-12 11:43:02.000000000 -0700
--- ../modules/imgproc/src/grabcut.cpp	2011-10-05 10:59:40.646173736 -0700
***************
*** 119,125 ****
      double res = 0;
      if( coefs[ci] > 0 )
      {
! 		CV_Assert( covDeterms[ci] > std::numeric_limits<double>::epsilon() );
          Vec3d diff = color;
          double* m = mean + 3*ci;
          diff[0] -= m[0]; diff[1] -= m[1]; diff[2] -= m[2];
--- 119,125 ----
      double res = 0;
      if( coefs[ci] > 0 )
      {
!     		CV_Assert( covDeterms[ci] > std::numeric_limits<double>::epsilon() );
          Vec3d diff = color;
          double* m = mean + 3*ci;
          diff[0] -= m[0]; diff[1] -= m[1]; diff[2] -= m[2];
***************
*** 173,179 ****
  
  void GMM::endLearning()
  {
-     const double variance = 0.01;
      for( int ci = 0; ci < componentsCount; ci++ )
      {
          int n = sampleCounts[ci];
--- 173,178 ----
***************
*** 191,205 ****
              c[3] = prods[ci][1][0]/n - m[1]*m[0]; c[4] = prods[ci][1][1]/n - m[1]*m[1]; c[5] = prods[ci][1][2]/n - m[1]*m[2];
              c[6] = prods[ci][2][0]/n - m[2]*m[0]; c[7] = prods[ci][2][1]/n - m[2]*m[1]; c[8] = prods[ci][2][2]/n - m[2]*m[2];
  
-             double dtrm = c[0]*(c[4]*c[8]-c[5]*c[7]) - c[1]*(c[3]*c[8]-c[5]*c[6]) + c[2]*(c[3]*c[7]-c[4]*c[6]);
-             if( dtrm <= std::numeric_limits<double>::epsilon() )
-             {
-                 // Adds the white noise to avoid singular covariance matrix.
-                 c[0] += variance;
-                 c[4] += variance;
-                 c[8] += variance;
-             }
- 
              calcInverseCovAndDeterm(ci);
          }
      }
--- 190,195 ----
***************
*** 210,217 ****
      if( coefs[ci] > 0 )
      {
          double *c = cov + 9*ci;
!         double dtrm =
!               covDeterms[ci] = c[0]*(c[4]*c[8]-c[5]*c[7]) - c[1]*(c[3]*c[8]-c[5]*c[6]) + c[2]*(c[3]*c[7]-c[4]*c[6]);
  
          CV_Assert( dtrm > std::numeric_limits<double>::epsilon() );
          inverseCovs[ci][0][0] =  (c[4]*c[8] - c[5]*c[7]) / dtrm;
--- 200,214 ----
      if( coefs[ci] > 0 )
      {
          double *c = cov + 9*ci;
!         double dtrm = c[0]*(c[4]*c[8]-c[5]*c[7]) - c[1]*(c[3]*c[8]-c[5]*c[6]) + c[2]*(c[3]*c[7]-c[4]*c[6]);
! 
!         if( !( dtrm > std::numeric_limits<double>::epsilon() ) )
!         {
!             const double epsilon = 0.00001;
!             dtrm = (c[0] + epsilon)*((c[4]+epsilon)*(c[8]+epsilon)-c[5]*c[7]) - c[1]*(c[3]*(c[8]+epsilon)-c[5]*c[6]) + c[2]*(c[3]*c[7]-(c[4]+epsilon)*c[6]);
!         }
!           
!         covDeterms[ci] = dtrm;
  
          CV_Assert( dtrm > std::numeric_limits<double>::epsilon() );
          inverseCovs[ci][0][0] =  (c[4]*c[8] - c[5]*c[7]) / dtrm;