예제 #1
0
파일: mapper.cpp 프로젝트: MRtrix3/mrtrix3
 void TrackMapper::set_factor (const Streamline<>& tck, SetVoxelExtras& out) const
 {
   factors.clear();
   factors.reserve (tck.size());
   load_factors (tck);
   gaussian_smooth_factors (tck);
   out.factor = 1.0;
 }
예제 #2
0
 bool Downsampler::operator() (const Streamline<>& in, Streamline<>& out) const
 {
   out.clear();
   out.index = in.index;
   out.weight = in.weight;
   if (ratio <= 1 || in.empty())
     return false;
   if (in.size() == 1)
     return true;
   out.push_back (in.front());
   const size_t midpoint = in.size()/2;
   size_t index = (((midpoint - 1) % ratio) + 1);
   while (index < in.size() - 1) {
     out.push_back (in[index]);
     index += ratio;
   }
   out.push_back (in.back());
   return true;
 }
예제 #3
0
        bool FixedNumPoints::operator() (const Streamline<>& in, Streamline<>& out) const
        {
          // Perform an explicit calculation of streamline length
          // From this, derive the spline position of each sample
          assert (in.size() > 1);
          out.clear();
          out.index = in.index;
          out.weight = in.weight;
          value_type length = 0.0;
          vector<value_type> steps;
          for (size_t i = 1; i != in.size(); ++i) {
            const value_type dist = (in[i] - in[i-1]).norm();
            length += dist;
            steps.push_back (dist);
          }
          steps.push_back (value_type(0));

          Math::Hermite<value_type> interp (hermite_tension);
          Streamline<> temp (in);
          const size_t s = temp.size();
          temp.insert    (temp.begin(), temp[0] + (temp[0] - temp[ 1 ]));
          temp.push_back (              temp[s] + (temp[s] - temp[s-1]));

          value_type cumulative_length = value_type(0);
          size_t input_index = 0;
          for (size_t output_index = 0; output_index != num_points; ++output_index) {
            const value_type target_length = length * output_index / value_type(num_points-1);
            while (input_index < s && (cumulative_length + steps[input_index] < target_length))
              cumulative_length += steps[input_index++];
            if (input_index == s) {
              out.push_back (temp[s]);
              break;
            }
            const value_type mu = (target_length - cumulative_length) / steps[input_index];
            interp.set (mu);
            out.push_back (interp.value (temp[input_index], temp[input_index+1], temp[input_index+2], temp[input_index+3]));
          }

          return true;
        }