contrib/gel/vifa/vifa_parallel.cxx

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// This is gel/vifa/vifa_parallel.cxx
#include "vifa_parallel.h"
//:
// \file
#include <vnl/vnl_math.h>
#include <vdgl/vdgl_digital_curve.h>
#include <vsol/vsol_curve_2d.h>
#include <vtol/vtol_edge_2d.h>
#include <vtol/vtol_vertex_2d.h>
#include <vtol/vtol_intensity_face.h>
#include "vifa_gaussian.h"

#ifdef DUMP
#include <vul/vul_sprintf.h>
#include <vcl_fstream.h>

static int pass = 0;
#endif

const float n_sigma = 2.0;  // on either side of center


vifa_parallel::
vifa_parallel(iface_list&   faces,
              bool          contrast_weighted,
              vifa_parallel_params*  params) :
  vifa_parallel_params(params)
{
  raw_h_ = new vifa_histogram(nbuckets, min_angle, max_angle);
  float  range = max_angle - min_angle;

  for (iface_iterator ifi = faces.begin(); ifi != faces.end(); ++ifi)
  {
    edge_list edges; (*ifi)->edges(edges);

    for (edge_iterator ei = edges.begin(); ei != edges.end(); ei++)
    {
      vtol_edge_2d* e = (*ei)->cast_to_edge_2d();

      if (e)
      {
#ifdef OLD_LINE_APPROX
        const vtol_vertex_2d*  v1 = e->v1()->cast_to_vertex_2d();
        const vtol_vertex_2d*  v2 = e->v2()->cast_to_vertex_2d();
        double dy = v1->y() - v2->y();
        double dx = v1->x() - v2->x();
        double length = 0.0;

        if (contrast_weighted)
        {
          vtol_intensity_face_sptr other_f = get_adjacent_iface(*ifi, e);

          if (other_f)
            length = vcl_sqrt((dx * dx) + (dy * dy))
                   * vcl_fabs((*ifi)->Io() - other_f->Io());
        }

        double  orientation = vcl_atan2(dy, dx) * vnl_math::deg_per_rad;
        if (orientation < 0)
          orientation += 180.0;

        float  theta = map_x(float(orientation));
        raw_h_->SetCount(theta, raw_h_->GetCount(theta) + float(length));
#else
        vsol_curve_2d_sptr  c = e->curve();

        if (c)
        {
          vdgl_digital_curve*  dc = c->cast_to_vdgl_digital_curve();

          if (dc)
          {
            double l = dc->length();

            for (int i = 0; i < l; i++)
            {
              // Use parametric index representation (0 -- 1)
              double theta = dc->get_theta(i / l);
#ifdef DEBUG
              vcl_cout << "raw theta: " << theta;
#endif
              while (theta < min_angle)
                theta += range;

              while (theta > max_angle)
                theta -= range;
#ifdef DEBUG
              vcl_cout << " to " << theta << vcl_endl;
#endif
              raw_h_->UpCount(float(theta));
            }
          }
        }
#endif  // OLD_LINE_APPROX
      }
    }
  }

  norm_h_ = vifa_parallel::normalize_histogram(raw_h_);
}


vifa_parallel::
vifa_parallel(vcl_vector<float>&  pixel_orientations,
              vifa_parallel_params*  params) :
  vifa_parallel_params(params)
{
  raw_h_ = new vifa_histogram(nbuckets, min_angle, max_angle);
  float  range = max_angle - min_angle;

  for (vcl_vector<float>::iterator p = pixel_orientations.begin();
       p != pixel_orientations.end(); ++p)
  {
    float  theta = (*p);

    while (theta < min_angle)
    {
      theta += range;
    }
    while (theta > max_angle)
    {
      theta -= range;
    }

    raw_h_->UpCount(theta);
  }

  norm_h_ = vifa_parallel::normalize_histogram(raw_h_);
}

vifa_parallel::
vifa_parallel(float  center_angle,
              float  std_dev)
{
  raw_h_ = new vifa_histogram(nbuckets, min_angle, max_angle);

#ifdef DEBUG
  vcl_cout << "vifa_parallel(): 0.5 is "<< raw_h_->GetValIndex(0.5) << vcl_endl;
#endif

  vifa_gaussian  g(center_angle, std_dev);
  for (float i = min_angle; i < 2 * max_angle; i++)
  {
    float  v = g.pdf(i);
    float  vx = map_x(i);

    raw_h_->SetCount(vx, raw_h_->GetCount(vx) + v);
  }

  norm_h_ = vifa_parallel::normalize_histogram(raw_h_);
}

vifa_parallel::~vifa_parallel()
{
  delete raw_h_;
  delete norm_h_;
}

void vifa_parallel::reset(void)
{
  delete norm_h_;
  norm_h_ = normalize_histogram(raw_h_);
}

vifa_histogram* vifa_parallel::
get_raw_hist(void)
{
  return raw_h_;
}

vifa_histogram* vifa_parallel::
get_norm_hist(void)
{
  return norm_h_;
}

void vifa_parallel::
map_gaussian(float&  max_angle,
             float&  std_dev,
             float&  scale)
{
  bool    set_min_res_flag = true;

  const float  incr = 3.0;  // put me in the params!
  float    max_value;
  float    local_max_angle = find_peak(max_value);
  max_angle = 0.0;
  std_dev = 0.0;
  scale = 0.0;

  // Skip histograms that are empty
  if (local_max_angle != -1.0)
  {
    float  min_residual = 0.f; // dummy initialisation

    for (float j=-(n_sigma+1); j<=(n_sigma+1); j++)
    {
      float  new_center = map_x(local_max_angle + (j * incr));
      float local_std_dev = 0.0;  // degrees

      for (int i = 0; i < 5; i++)
      {
        local_std_dev += incr;
        vifa_gaussian  g(new_center, local_std_dev);
        float      g_max = g.pdf(new_center);
        float      local_scale = norm_h_->GetCount(new_center) /
                        g_max;
        // NOTE: local_scale could be zero if the histogram is 0 here...

#ifdef DUMP
        char      buf[25];
        vul_sprintf(buf, "gauss-%d-%d-%d.dat", pass, (int)j, i);
        vcl_ofstream  gdump(buf);
#endif
        // int    sample_count = 0;
        float  sample_sum = 0.0;

        for (float  dx = (-n_sigma * local_std_dev);
             dx <= (n_sigma * local_std_dev);
             dx += norm_h_->GetBucketSize())
        {
          float  vx = new_center + dx;
          float  e = g.pdf(vx) * local_scale;
          // e could be zero because of local_scale, see above
          float  x = map_x(vx);
          float  f = norm_h_->GetCount(x);
          if (f < 0)
          {
            f = 0;
          }

          float  diff = vcl_fabs(f - e);

#ifdef DUMP
          gdump << x << ' ' << e << ' ' << diff << ' ' << vx << ' ' << f << vcl_endl;
#endif
          if (e != 0.0)
          {
            sample_sum += ((diff * diff) / e);
            // sample_count++;
          }
        }

        // Set min_residual the first time thru
        if ((set_min_res_flag || sample_sum < min_residual) && sample_sum != 0)
        {
          set_min_res_flag = false;
          min_residual = sample_sum;
          std_dev = local_std_dev;
          max_angle = new_center;
          scale = local_scale;

#ifdef DEBUG
          vcl_cout << "*** ";
#endif
        }

#ifdef DEBUG
        vcl_cout << j << " gaussian " << i << " residual "
                 << sample_sum << " sample count " << sample_count << vcl_endl;
#endif
      }
    }

#ifdef DEBUG
    vcl_cout << "best is at " << max_angle << " sd of " << std_dev
             << " scale " << scale << vcl_endl;
#endif

#ifdef DUMP
    pass++;
#endif
  }
}

void vifa_parallel::
remove_gaussian(float  max_angle,
                float  std_dev,
                float  scale)
{
  // Skip if histogram is empty
  if (norm_h_->GetMaxCount() != 0.0)
  {
    vifa_gaussian  g(max_angle, std_dev);
    for (float  dx = (-n_sigma * std_dev);
         dx <= (n_sigma * std_dev);
         dx += norm_h_->GetBucketSize())
    {
      float  vx = max_angle + dx;
      float  e = g.pdf(vx) * scale;
      float  x = map_x(vx);
      float  f = norm_h_->GetCount(x);

      if (f >= 0)
      {
        float  new_val = ((f - e) < 0) ? 0 : (f - e);

#ifdef DEBUG
        vcl_cout << "  --- " << x << ": " << f <<" to " << new_val << vcl_endl;
#endif

        norm_h_->SetCount(x, new_val);
      }
      else
      {
        vcl_cerr << "  --- " << x << ": bad " <<
          norm_h_->GetValIndex(x) << vcl_endl;
      }
    }
  }
}

void vifa_parallel::
snapshot(char* fname)
{
  norm_h_->WritePlot(fname);
}

float vifa_parallel::
area(void)
{
  if (norm_h_->GetMaxCount() == 0.0)
  {
    // Return 0 area for empty histograms
    return 0.0;
  }
  else
  {
    return norm_h_->ComputeArea();
  }
}

float vifa_parallel::
bin_variance(void)
{
  float* counts = norm_h_->GetCounts();
  int    res = norm_h_->GetRes();
  float  sum = 0;
  float  sum2 = 0;

  for (int i = 0; i < res; i++)
  {
    sum += counts[i];
    sum2 += (counts[i] * counts[i]);
  }

  float mean = sum / res;
  float var = (sum2 / res) - (mean * mean);

  return var;
}

float vifa_parallel::
map_x(float  raw_x)
{
  float  range = max_angle - min_angle + 1;

  while (raw_x < min_angle)
  {
    raw_x += range;
  }
  while (raw_x > max_angle)
  {
    raw_x -= range;
  }

  return raw_x;
}

vifa_histogram* vifa_parallel::
normalize_histogram(vifa_histogram* h)
{
  vifa_histogram*  norm = new vifa_histogram(nbuckets, min_angle, max_angle);
  int        nbuckets = h->GetRes();
  float      area = h->ComputeArea();
  float*      x_vals = h->GetVals();
  float*      y_vals = h->GetCounts();

  for (int i = 0; i < nbuckets; i++)
  {
    float  new_area = y_vals[i] / area;
    norm->SetCount(x_vals[i], new_area);
  }

  return norm;
}

float vifa_parallel::
find_peak(float&  max_value)
{
  int    nbuckets = norm_h_->GetRes();
  float*  x_vals = norm_h_->GetVals();
  float*  y_vals = norm_h_->GetCounts();
  int    max_index = -1;
  max_value = -1;

  for (int i = 0; i < nbuckets; i++)
  {
    if (y_vals[i] > max_value)
    {
      max_index = i;
      max_value = y_vals[i];
    }
  }

  if (max_index == -1)
  {
    return -1;
  }

  max_value = y_vals[max_index];
  return x_vals[max_index];
}

vtol_intensity_face_sptr vifa_parallel::
get_adjacent_iface(vtol_intensity_face_sptr  known_face,
                   vtol_edge_2d*         e)
{
  vtol_intensity_face_sptr  adj_face = 0;
  face_list faces; e->faces(faces);

  // Expect only two intensity faces for 2-D case
  if (faces.size() == 2)
  {
    vtol_intensity_face* f1 = faces[0]->cast_to_intensity_face();
    vtol_intensity_face* f2 = faces[1]->cast_to_intensity_face();

    if (f1 && f2)
    {
      if (*known_face == *f1)
      {
        adj_face = f2;
      }
      else if (*known_face == *f2)
      {
        adj_face = f1;
      }
      else
      {
        // Known face does not contain the
        // given edge -- leave result NULL
      }
    }
  }
  return adj_face;
}