tesseract::DetLineFit Class Reference

#include <detlinefit.h>

List of all members.

Public Member Functions
	DetLineFit ()
	~DetLineFit ()
void	Clear ()
void	Add (const ICOORD &pt)
double	Fit (ICOORD *pt1, ICOORD *pt2)
double	Fit (float *m, float *c)
double	ConstrainedFit (double m, float *c)

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Detailed Description

Definition at line 54 of file detlinefit.h.

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Constructor & Destructor Documentation

tesseract::DetLineFit::DetLineFit

(

)

Definition at line 29 of file detlinefit.cpp.

                       {
}

tesseract::DetLineFit::~DetLineFit

(

)

Definition at line 32 of file detlinefit.cpp.

                        {
}

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Member Function Documentation

void tesseract::DetLineFit::Add

(

const ICOORD &

pt

)

Definition at line 41 of file detlinefit.cpp.

                                     {
  ICOORDELT_IT it = &pt_list_;
  ICOORDELT* new_pt = new ICOORDELT(pt);
  it.add_to_end(new_pt);
}

void tesseract::DetLineFit::Clear

(

)

Definition at line 36 of file detlinefit.cpp.

                       {
  pt_list_.clear();
}

double tesseract::DetLineFit::ConstrainedFit	(	double	m,
		float *	c
	)

Definition at line 159 of file detlinefit.cpp.

                                                    {
  ICOORDELT_IT it(&pt_list_);
  // Do something sensible with no points.
  if (pt_list_.empty()) {
    *c = 0.0f;
    return 0.0;
  }
  // Count the points and find the first and last kNumEndPoints.
  // Put the ends in a single array to make their use easier later.
  ICOORD* pts[kNumEndPoints * 2];
  int pt_count = 0;
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    if (pt_count < kNumEndPoints) {
      pts[pt_count] = it.data();
      pts[kNumEndPoints + pt_count] = pts[pt_count];
    } else {
      for (int i = 1; i < kNumEndPoints; ++i)
        pts[kNumEndPoints + i - 1] = pts[kNumEndPoints + i];
      pts[kNumEndPoints * 2 - 1] = it.data();
    }
    ++pt_count;
  }
  while (pt_count < kNumEndPoints) {
    pts[pt_count] = NULL;
    pts[kNumEndPoints + pt_count++] = NULL;
  }
  int* distances = new int[pt_count];
  double best_uq = -1.0;
  // Iterate each pair of points and find the best fitting line.
  for (int i = 0; i < kNumEndPoints * 2; ++i) {
    ICOORD* start = pts[i];
    if (start == NULL) continue;
    ICOORD end = ComputeEndFromGradient(*start, m);
    // Compute the upper quartile error from the line.
    double dist = ComputeErrors(*start, end, distances);
    if (dist < best_uq || best_uq < 0.0) {
      best_uq = dist;
      *c = start->y() - start->x() * m;
    }
  }
  delete [] distances;
  // Finally compute the square root to return the true distance.
  return best_uq > 0.0 ? sqrt(best_uq) : best_uq;
}

double tesseract::DetLineFit::Fit	(	ICOORD *	pt1,
		ICOORD *	pt2
	)

Definition at line 49 of file detlinefit.cpp.

                                               {
  ICOORDELT_IT it(&pt_list_);
  // Do something sensible with no points.
  if (pt_list_.empty()) {
    pt1->set_x(0);
    pt1->set_y(0);
    *pt2 = *pt1;
    return 0.0;
  }
  // Count the points and find the first and last kNumEndPoints.
  ICOORD* starts[kNumEndPoints];
  ICOORD* ends[kNumEndPoints];
  int pt_count = 0;
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    if (pt_count < kNumEndPoints) {
      starts[pt_count] = it.data();
      ends[pt_count] = starts[pt_count];
    } else {
      for (int i = 1; i < kNumEndPoints; ++i)
        ends[i - 1] = ends[i];
      ends[kNumEndPoints - 1] = it.data();
    }
    ++pt_count;
  }
  // 1 or 2 points need special treatment.
  if (pt_count <= 2) {
    *pt1 = *starts[0];
    if (pt_count > 1)
      *pt2 = *starts[1];
    else
      *pt2 = *pt1;
    return 0.0;
  }
  int end_count = MIN(pt_count, kNumEndPoints);
  int* distances = new int[pt_count];
  double best_uq = -1.0;
  // Iterate each pair of points and find the best fitting line.
  for (int i = 0; i < end_count; ++i) {
    ICOORD* start = starts[i];
    for (int j = 0; j < end_count; ++j) {
      ICOORD* end = ends[j];
      if (start != end) {
        // Compute the upper quartile error from the line.
        double dist = ComputeErrors(*start, *end, distances);
        if (dist < best_uq || best_uq < 0.0) {
          best_uq = dist;
          *pt1 = *start;
          *pt2 = *end;
        }
      }
    }
  }
  delete [] distances;
  // Finally compute the square root to return the true distance.
  return best_uq > 0.0 ? sqrt(best_uq) : best_uq;
}

double tesseract::DetLineFit::Fit	(	float *	m,
		float *	c
	)

Definition at line 109 of file detlinefit.cpp.

                                         {
  ICOORD start, end;
  double error = Fit(&start, &end);
  if (end.x() != start.x()) {
    *m = static_cast<float>(end.y() - start.y()) / (end.x() - start.x());
    *c = start.y() - *m * start.x();
  } else {
    *m = 0.0f;
    *c = 0.0f;
  }
  return error;
}

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The documentation for this class was generated from the following files:

• tesseract-ocr/ccstruct/detlinefit.h
• tesseract-ocr/ccstruct/detlinefit.cpp