tesseract::TabVector Class Reference

#include <tabvector.h>

Inheritance diagram for tesseract::TabVector:

List of all members.

Public Member Functions
	TabVector ()
	~TabVector ()
	TabVector (const TabVector &src, TabAlignment alignment, const ICOORD &vertical_skew, BLOBNBOX *blob)
TabVector *	ShallowCopy () const
const ICOORD &	startpt () const
const ICOORD &	endpt () const
int	extended_ymax () const
int	extended_ymin () const
int	sort_key () const
int	mean_width () const
void	set_top_constraints (TabConstraint_LIST *constraints)
void	set_bottom_constraints (TabConstraint_LIST *constraints)
TabVector_CLIST *	partners ()
void	set_startpt (const ICOORD &start)
void	set_endpt (const ICOORD &end)
bool	intersects_other_lines () const
void	set_intersects_other_lines (bool value)
int	XAtY (int y) const
int	VOverlap (const TabVector &other) const
int	VOverlap (int top_y, int bottom_y) const
int	ExtendedOverlap (int top_y, int bottom_y) const
bool	IsLeftTab () const
bool	IsRightTab () const
bool	IsSeparator () const
bool	IsCenterTab () const
bool	IsRagged () const
bool	IsLeftOf (const TabVector &other) const
bool	Partnerless ()
int	BoxCount ()
void	Freeze ()
void	XYFlip ()
void	ReflectInYAxis ()
void	ExtendToBox (BLOBNBOX *blob)
void	SetYStart (int start_y)
void	SetYEnd (int end_y)
void	Rotate (const FCOORD &rotation)
void	SetupConstraints ()
void	SetupPartnerConstraints ()
void	SetupPartnerConstraints (TabVector *partner)
void	ApplyConstraints ()
bool	SimilarTo (const ICOORD &vertical, const TabVector &other, BlobGrid *grid) const
void	MergeWith (const ICOORD &vertical, TabVector *other)
void	AddPartner (TabVector *partner)
bool	IsAPartner (const TabVector *other)
void	Print (const char *prefix)
void	Debug (const char *prefix)
void	Display (ScrollView *tab_win)
void	FitAndEvaluateIfNeeded (const ICOORD &vertical, TabFind *finder)
void	Evaluate (const ICOORD &vertical, TabFind *finder)
bool	Fit (ICOORD vertical, bool force_parallel)
TabVector *	VerticalTextlinePartner ()
TabVector *	GetSinglePartner ()
Static Public Member Functions
static TabVector *	FitVector (TabAlignment alignment, ICOORD vertical, int extended_start_y, int extended_end_y, BLOBNBOX_CLIST *good_points, int *vertical_x, int *vertical_y)
static int	SortKey (const ICOORD &vertical, int x, int y)
static int	XAtY (const ICOORD &vertical, int sort_key, int y)
static int	SortVectorsByKey (const void *v1, const void *v2)
static void	MergeSimilarTabVectors (const ICOORD &vertical, TabVector_LIST *vectors, BlobGrid *grid)

---

Detailed Description

Definition at line 111 of file tabvector.h.

---

Constructor & Destructor Documentation

tesseract::TabVector::TabVector

(

)

[inline]

Definition at line 113 of file tabvector.h.

              {
    // TODO(rays) fix this in elst.h line 1076, where it should use the
    // copy constructor instead of operator=.
  }

tesseract::TabVector::~TabVector

(

)

Definition at line 171 of file tabvector.cpp.

                      {
}

tesseract::TabVector::TabVector	(	const TabVector &	src,
		TabAlignment	alignment,
		const ICOORD &	vertical_skew,
		BLOBNBOX *	blob
	)

Definition at line 205 of file tabvector.cpp.

  : extended_ymin_(src.extended_ymin_), extended_ymax_(src.extended_ymax_),
    sort_key_(0), percent_score_(0), mean_width_(0),
    needs_refit_(true), needs_evaluation_(true), intersects_other_lines_(false),
    alignment_(alignment),
    top_constraints_(NULL), bottom_constraints_(NULL) {
  BLOBNBOX_C_IT it(&boxes_);
  it.add_to_end(blob);
  TBOX box = blob->bounding_box();
  if (IsLeftTab()) {
    startpt_ = box.botleft();
    endpt_ = box.topleft();
  } else {
    startpt_ = box.botright();
    endpt_ = box.topright();
  }
  sort_key_ = SortKey(vertical_skew,
                      (startpt_.x() + endpt_.x()) / 2,
                      (startpt_.y() + endpt_.y()) / 2);
  if (textord_debug_tabfind > 3)
    Print("Constructed a new tab vector:");
}

---

Member Function Documentation

void tesseract::TabVector::AddPartner

(

TabVector *

partner

)

Definition at line 493 of file tabvector.cpp.

                                             {
  if (IsSeparator() || partner->IsSeparator())
    return;
  TabVector_C_IT it(&partners_);
  if (!it.empty()) {
    it.move_to_last();
    if (it.data() == partner)
      return;
  }
  it.add_after_then_move(partner);
}

void tesseract::TabVector::ApplyConstraints

(

)

Definition at line 354 of file tabvector.cpp.

                                 {
  if (top_constraints_ != NULL)
    TabConstraint::ApplyConstraints(top_constraints_);
  if (bottom_constraints_ != NULL)
    TabConstraint::ApplyConstraints(bottom_constraints_);
}

int tesseract::TabVector::BoxCount

(

)

[inline]

Definition at line 245 of file tabvector.h.

                 {
    return boxes_.length();
  }

void tesseract::TabVector::Debug

(

const char *

prefix

)

Definition at line 540 of file tabvector.cpp.

                                        {
  Print(prefix);
  BLOBNBOX_C_IT it(&boxes_);
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    BLOBNBOX* bbox = it.data();
    const TBOX& box = bbox->bounding_box();
    tprintf("Box at (%d,%d)->(%d,%d)\n",
            box.left(), box.bottom(), box.right(), box.top());
  }
}

void tesseract::TabVector::Display

(

ScrollView *

tab_win

)

Definition at line 552 of file tabvector.cpp.

                                           {
#ifndef GRAPHICS_DISABLED
  if (textord_debug_printable)
    tab_win->Pen(ScrollView::BLUE);
  else if (alignment_ == TA_LEFT_ALIGNED)
    tab_win->Pen(ScrollView::LIME_GREEN);
  else if (alignment_ == TA_LEFT_RAGGED)
    tab_win->Pen(ScrollView::DARK_GREEN);
  else if (alignment_ == TA_RIGHT_ALIGNED)
    tab_win->Pen(ScrollView::PINK);
  else if (alignment_ == TA_RIGHT_RAGGED)
    tab_win->Pen(ScrollView::CORAL);
  else
    tab_win->Pen(ScrollView::WHITE);
  tab_win->Line(startpt_.x(), startpt_.y(), endpt_.x(), endpt_.y());
  tab_win->Pen(ScrollView::GREY);
  tab_win->Line(startpt_.x(), startpt_.y(), startpt_.x(), extended_ymin_);
  tab_win->Line(endpt_.x(), extended_ymax_, endpt_.x(), endpt_.y());
  char score_buf[64];
  snprintf(score_buf, sizeof(score_buf), "%d", percent_score_);
  tab_win->TextAttributes("Times", 50, false, false, false);
  tab_win->Text(startpt_.x(), startpt_.y(), score_buf);
#endif
}

const ICOORD& tesseract::TabVector::endpt

(

)

const [inline]

Definition at line 149 of file tabvector.h.

                              {
    return endpt_;
  }

void tesseract::TabVector::Evaluate	(	const ICOORD &	vertical,
		TabFind *	finder
	)

Definition at line 592 of file tabvector.cpp.

                                                                {
  bool debug = false;
  needs_evaluation_ = false;
  int length = endpt_.y() - startpt_.y();
  if (length == 0 || boxes_.empty()) {
    percent_score_ = 0;
    Print("Zero length in evaluate");
    return;
  }
  // Compute the mean box height.
  BLOBNBOX_C_IT it(&boxes_);
  int mean_height = 0;
  int height_count = 0;
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    BLOBNBOX* bbox = it.data();
    const TBOX& box = bbox->bounding_box();
    int height = box.height();
    mean_height += height;
    ++height_count;
  }
  mean_height /= height_count;
  int max_gutter = kGutterMultiple * mean_height;
  if (IsRagged()) {
    // Ragged edges face a tougher test in that the gap must always be within
    // the height of the blob.
    max_gutter = kGutterToNeighbourRatio * mean_height;
  }

  STATS gutters(0, max_gutter + 1);
  // Evaluate the boxes for their goodness, calculating the coverage as we go.
  // Remove boxes that are not good and shorten the list to the first and
  // last good boxes.
  int num_deleted_boxes = 0;
  bool text_on_image = false;
  int good_length = 0;
  const TBOX* prev_good_box = NULL;
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    BLOBNBOX* bbox = it.data();
    const TBOX& box = bbox->bounding_box();
    int mid_y = (box.top() + box.bottom()) / 2;
    if (TabFind::WithinTestRegion(2, XAtY(box.bottom()), box.bottom())) {
      if (!debug) {
        tprintf("After already deleting %d boxes, ", num_deleted_boxes);
        Print("Starting evaluation");
      }
      debug = true;
    }
    // A good box is one where the nearest neighbour on the inside is closer
    // than half the distance to the nearest neighbour on the outside
    // (of the putative column).
    bool left = IsLeftTab();
    int tab_x = XAtY(mid_y);
    int gutter_width;
    int neighbour_gap;
    finder->GutterWidthAndNeighbourGap(tab_x, mean_height, max_gutter, left,
                                       bbox, &gutter_width, &neighbour_gap);
    if (debug) {
      tprintf("Box (%d,%d)->(%d,%d) has gutter %d, ndist %d\n",
              box.left(), box.bottom(), box.right(), box.top(),
              gutter_width, neighbour_gap);
    }
    // Now we can make the test.
    if (neighbour_gap * kGutterToNeighbourRatio <= gutter_width) {
      // A good box contributes its height to the good_length.
      good_length += box.top() - box.bottom();
      gutters.add(gutter_width, 1);
      // Two good boxes together contribute the gap between them
      // to the good_length as well, as long as the gap is not
      // too big.
      if (prev_good_box != NULL) {
        int vertical_gap = box.bottom() - prev_good_box->top();
        double size1 = sqrt(static_cast<double>(prev_good_box->area()));
        double size2 = sqrt(static_cast<double>(box.area()));
        if (vertical_gap < kMaxFillinMultiple * MIN(size1, size2))
          good_length += vertical_gap;
        if (debug) {
          tprintf("Box and prev good, gap=%d, target %g, goodlength=%d\n",
                  vertical_gap, kMaxFillinMultiple * MIN(size1, size2),
                  good_length);
        }
      } else {
        // Adjust the start to the first good box.
        SetYStart(box.bottom());
      }
      prev_good_box = &box;
      if (bbox->flow() == BTFT_TEXT_ON_IMAGE)
        text_on_image = true;
    } else {
      // Get rid of boxes that are not good.
      if (debug) {
        tprintf("Bad Box (%d,%d)->(%d,%d) with gutter %d, ndist %d\n",
                box.left(), box.bottom(), box.right(), box.top(),
                gutter_width, neighbour_gap);
      }
      it.extract();
      ++num_deleted_boxes;
    }
  }
  if (debug) {
    Print("Evaluating:");
  }
  // If there are any good boxes, do it again, except this time get rid of
  // boxes that have a gutter that is a small fraction of the mean gutter.
  // This filters out ends that run into a coincidental gap in the text.
  int search_top = endpt_.y();
  int search_bottom = startpt_.y();
  int median_gutter = IntCastRounded(gutters.median());
  if (gutters.get_total() > 0) {
    prev_good_box = NULL;
    for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
      BLOBNBOX* bbox = it.data();
      const TBOX& box = bbox->bounding_box();
      int mid_y = (box.top() + box.bottom()) / 2;
      // A good box is one where the gutter width is at least some constant
      // fraction of the mean gutter width.
      bool left = IsLeftTab();
      int tab_x = XAtY(mid_y);
      int max_gutter = kGutterMultiple * mean_height;
      if (IsRagged()) {
        // Ragged edges face a tougher test in that the gap must always be
        // within the height of the blob.
        max_gutter = kGutterToNeighbourRatio * mean_height;
      }
      int gutter_width;
      int neighbour_gap;
      finder->GutterWidthAndNeighbourGap(tab_x, mean_height, max_gutter, left,
                                         bbox, &gutter_width, &neighbour_gap);
      // Now we can make the test.
      if (gutter_width >= median_gutter * kMinGutterFraction) {
        if (prev_good_box == NULL) {
          // Adjust the start to the first good box.
          SetYStart(box.bottom());
          search_bottom = box.top();
        }
        prev_good_box = &box;
        search_top = box.bottom();
      } else {
        // Get rid of boxes that are not good.
        if (debug) {
          tprintf("Bad Box (%d,%d)->(%d,%d) with gutter %d, mean gutter %d\n",
                  box.left(), box.bottom(), box.right(), box.top(),
                  gutter_width, median_gutter);
        }
        it.extract();
        ++num_deleted_boxes = true;
      }
    }
  }
  // If there has been a good box, adjust the end.
  if (prev_good_box != NULL) {
    SetYEnd(prev_good_box->top());
    // Compute the percentage of the vector that is occupied by good boxes.
    int length = endpt_.y() - startpt_.y();
    percent_score_ = 100 * good_length / length;
    if (num_deleted_boxes > 0) {
      needs_refit_ = true;
      FitAndEvaluateIfNeeded(vertical, finder);
      if (boxes_.empty())
        return;
    }
    // Test the gutter over the whole vector, instead of just at the boxes.
    int required_shift;
    if (search_bottom > search_top) {
      search_bottom = startpt_.y();
      search_top = endpt_.y();
    }
    double min_gutter_width = kLineCountReciprocal / boxes_.length();
    min_gutter_width += IsRagged() ? kMinRaggedGutter : kMinAlignedGutter;
    min_gutter_width *= mean_height;
    int max_gutter_width = IntCastRounded(min_gutter_width) + 1;
    if (median_gutter > max_gutter_width)
      max_gutter_width = median_gutter;
    int gutter_width = finder->GutterWidth(search_bottom, search_top, *this,
                                           text_on_image, max_gutter_width,
                                           &required_shift);
    if (gutter_width < min_gutter_width) {
      if (debug) {
        tprintf("Rejecting bad tab Vector with %d gutter vs %g min\n",
                gutter_width, min_gutter_width);
      }
      boxes_.shallow_clear();
      percent_score_ = 0;
    } else if (debug) {
      tprintf("Final gutter %d, vs limit of %g, required shift = %d\n",
              gutter_width, min_gutter_width, required_shift);
    }
  } else {
    // There are no good boxes left, so score is 0.
    percent_score_ = 0;
  }

  if (debug) {
    Print("Evaluation complete:");
  }
}

int tesseract::TabVector::extended_ymax

(

)

const [inline]

Definition at line 152 of file tabvector.h.

                            {
    return extended_ymax_;
  }

int tesseract::TabVector::extended_ymin

(

)

const [inline]

Definition at line 155 of file tabvector.h.

                            {
    return extended_ymin_;
  }

int tesseract::TabVector::ExtendedOverlap	(	int	top_y,
		int	bottom_y
	)		const [inline]

Definition at line 208 of file tabvector.h.

                                                     {
    return MIN(top_y, extended_ymax_) - MAX(bottom_y, extended_ymin_);
  }

void tesseract::TabVector::ExtendToBox

(

BLOBNBOX *

blob

)

Definition at line 247 of file tabvector.cpp.

                                              {
  TBOX new_box = new_blob->bounding_box();
  BLOBNBOX_C_IT it(&boxes_);
  if (!it.empty()) {
    BLOBNBOX* blob = it.data();
    TBOX box = blob->bounding_box();
    while (!it.at_last() && box.top() <= new_box.top()) {
      if (blob == new_blob)
        return;  // We have it already.
      it.forward();
      blob = it.data();
      box = blob->bounding_box();
    }
    if (box.top() >= new_box.top()) {
      it.add_before_stay_put(new_blob);
      needs_refit_ = true;
      return;
    }
  }
  needs_refit_ = true;
  it.add_after_stay_put(new_blob);
}

bool tesseract::TabVector::Fit	(	ICOORD	vertical,
		bool	force_parallel
	)

Definition at line 793 of file tabvector.cpp.

                                                        {
  needs_refit_ = false;
  if (boxes_.empty()) {
    // Don't refit something with no boxes, as that only happens
    // in Evaluate, and we don't want to end up with a zero vector.
    if (!force_parallel)
      return false;
    // If we are forcing parallel, then we just need to set the sort_key_.
    ICOORD midpt = startpt_;
    midpt += endpt_;
    midpt /= 2;
    sort_key_ = SortKey(vertical, midpt.x(), midpt.y());
    return startpt_.y() != endpt_.y();
  }
  if (!force_parallel && !IsRagged()) {
    // Use a fitted line as the vertical.
    DetLineFit linepoints;
    BLOBNBOX_C_IT it(&boxes_);
    // Fit a line to all the boxes in the list.
    for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
      BLOBNBOX* bbox = it.data();
      TBOX box = bbox->bounding_box();
      int x1 = IsRightTab() ? box.right() : box.left();
      ICOORD boxpt(x1, box.bottom());
      linepoints.Add(boxpt);
      if (it.at_last()) {
        ICOORD top_pt(x1, box.top());
        linepoints.Add(top_pt);
      }
    }
    linepoints.Fit(&startpt_, &endpt_);
    if (startpt_.y() != endpt_.y()) {
      vertical = endpt_;
      vertical -= startpt_;
    }
  }
  int start_y = startpt_.y();
  int end_y = endpt_.y();
  sort_key_ = IsLeftTab() ? MAX_INT32 : -MAX_INT32;
  BLOBNBOX_C_IT it(&boxes_);
  // Choose a line parallel to the vertical such that all boxes are on the
  // correct side of it.
  mean_width_ = 0;
  int width_count = 0;
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    BLOBNBOX* bbox = it.data();
    TBOX box = bbox->bounding_box();
    mean_width_ += box.width();
    ++width_count;
    int x1 = IsRightTab() ? box.right() : box.left();
    // Test both the bottom and the top, as one will be more extreme, depending
    // on the direction of skew.
    int bottom_y = box.bottom();
    int top_y = box.top();
    int key = SortKey(vertical, x1, bottom_y);
    if (IsLeftTab() == (key < sort_key_)) {
      sort_key_ = key;
      startpt_ = ICOORD(x1, bottom_y);
    }
    key = SortKey(vertical, x1, top_y);
    if (IsLeftTab() == (key < sort_key_)) {
      sort_key_ = key;
      startpt_ = ICOORD(x1, top_y);
    }
    if (it.at_first())
      start_y = bottom_y;
    if (it.at_last())
      end_y = top_y;
  }
  if (width_count > 0) {
    mean_width_ = (mean_width_ + width_count - 1) / width_count;
  }
  endpt_ = startpt_ + vertical;
  needs_evaluation_ = true;
  if (start_y != end_y) {
    // Set the ends of the vector to fully include the first and last blobs.
    startpt_.set_x(XAtY(vertical, sort_key_, start_y));
    startpt_.set_y(start_y);
    endpt_.set_x(XAtY(vertical, sort_key_, end_y));
    endpt_.set_y(end_y);
    return true;
  }
  return false;
}

void tesseract::TabVector::FitAndEvaluateIfNeeded	(	const ICOORD &	vertical,
		TabFind *	finder
	)

Definition at line 578 of file tabvector.cpp.

                                                        {
  if (needs_refit_)
    Fit(vertical, true);
  if (needs_evaluation_)
    Evaluate(vertical, finder);
}

TabVector * tesseract::TabVector::FitVector	(	TabAlignment	alignment,
		ICOORD	vertical,
		int	extended_start_y,
		int	extended_end_y,
		BLOBNBOX_CLIST *	good_points,
		int *	vertical_x,
		int *	vertical_y
	)		[static]

Definition at line 183 of file tabvector.cpp.

                                                                  {
  TabVector* vector = new TabVector(extended_start_y, extended_end_y,
                                    alignment, good_points);
  if (!vector->Fit(vertical, false)) {
    delete vector;
    return NULL;
  }
  if (!vector->IsRagged()) {
    vertical = vector->endpt_ - vector->startpt_;
    int weight = vector->BoxCount();
    *vertical_x += vertical.x() * weight;
    *vertical_y += vertical.y() * weight;
  }
  return vector;
}

void tesseract::TabVector::Freeze

(

)

[inline]

Definition at line 250 of file tabvector.h.

                {
    boxes_.shallow_clear();
  }

TabVector * tesseract::TabVector::GetSinglePartner

(

)

Definition at line 879 of file tabvector.cpp.

                                       {
  if (!partners_.singleton())
    return NULL;
  TabVector_C_IT partner_it(&partners_);
  TabVector* partner = partner_it.data();
  return partner;
}

bool tesseract::TabVector::intersects_other_lines

(

)

const [inline]

Definition at line 179 of file tabvector.h.

                                      {
    return intersects_other_lines_;
  }

bool tesseract::TabVector::IsAPartner

(

const TabVector *

other

)

Definition at line 506 of file tabvector.cpp.

                                                 {
  TabVector_C_IT it(&partners_);
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    if (it.data() == other)
      return true;
  }
  return false;
}

bool tesseract::TabVector::IsCenterTab

(

)

const [inline]

Definition at line 225 of file tabvector.h.

                           {
    return alignment_ == TA_CENTER_JUSTIFIED;
  }

bool tesseract::TabVector::IsLeftOf

(

const TabVector &

other

)

const [inline]

Definition at line 235 of file tabvector.h.

                                              {
    return sort_key_ < other.sort_key_;
  }

bool tesseract::TabVector::IsLeftTab

(

)

const [inline]

Definition at line 213 of file tabvector.h.

                         {
    return alignment_ == TA_LEFT_ALIGNED || alignment_ == TA_LEFT_RAGGED;
  }

bool tesseract::TabVector::IsRagged

(

)

const [inline]

Definition at line 229 of file tabvector.h.

                        {
    return alignment_ == TA_LEFT_RAGGED || alignment_ == TA_RIGHT_RAGGED;
  }

bool tesseract::TabVector::IsRightTab

(

)

const [inline]

Definition at line 217 of file tabvector.h.

                          {
    return alignment_ == TA_RIGHT_ALIGNED || alignment_ == TA_RIGHT_RAGGED;
  }

bool tesseract::TabVector::IsSeparator

(

)

const [inline]

Definition at line 221 of file tabvector.h.

                           {
    return alignment_ == TA_SEPARATOR;
  }

int tesseract::TabVector::mean_width

(

)

const [inline]

Definition at line 161 of file tabvector.h.

                         {
    return mean_width_;
  }

void tesseract::TabVector::MergeSimilarTabVectors	(	const ICOORD &	vertical,
		TabVector_LIST *	vectors,
		BlobGrid *	grid
	)		[static]

Definition at line 362 of file tabvector.cpp.

                                                       {
  TabVector_IT it1(vectors);
  for (it1.mark_cycle_pt(); !it1.cycled_list(); it1.forward()) {
    TabVector* v1 = it1.data();
    TabVector_IT it2(it1);
    for (it2.forward(); !it2.at_first(); it2.forward()) {
      TabVector* v2 = it2.data();
      if (v2->SimilarTo(vertical, *v1, grid)) {
        // Merge into the forward one, in case the combined vector now
        // overlaps one in between.
        if (textord_debug_tabfind) {
          v2->Print("Merging");
          v1->Print("by deleting");
        }
        v2->MergeWith(vertical, it1.extract());
        if (textord_debug_tabfind) {
          v2->Print("Producing");
        }
        ICOORD merged_vector = v2->endpt();
        merged_vector -= v2->startpt();
        if (abs(merged_vector.x()) > 100) {
          v2->Print("Garbage result of merge?");
        }
        break;
      }
    }
  }
}

void tesseract::TabVector::MergeWith	(	const ICOORD &	vertical,
		TabVector *	other
	)

Definition at line 459 of file tabvector.cpp.

                                                                  {
  extended_ymin_ = MIN(extended_ymin_, other->extended_ymin_);
  extended_ymax_ = MAX(extended_ymax_, other->extended_ymax_);
  if (other->IsRagged()) {
    alignment_ = other->alignment_;
  }
  // Merge sort the two lists of boxes.
  BLOBNBOX_C_IT it1(&boxes_);
  BLOBNBOX_C_IT it2(&other->boxes_);
  while (!it2.empty()) {
    BLOBNBOX* bbox2 = it2.extract();
    it2.forward();
    TBOX box2 = bbox2->bounding_box();
    BLOBNBOX* bbox1 = it1.data();
    TBOX box1 = bbox1->bounding_box();
    while (box1.bottom() < box2.bottom() && !it1.at_last()) {
      it1.forward();
      bbox1 = it1.data();
      box1 = bbox1->bounding_box();
    }
    if (box1.bottom() < box2.bottom()) {
      it1.add_to_end(bbox2);
    } else if (bbox1 != bbox2) {
      it1.add_before_stay_put(bbox2);
    }
  }
  Fit(vertical, true);
  other->Delete(this);
}

bool tesseract::TabVector::Partnerless

(

)

[inline]

Definition at line 240 of file tabvector.h.

                     {
    return partners_.empty();
  }

TabVector_CLIST* tesseract::TabVector::partners

(

)

[inline]

Definition at line 170 of file tabvector.h.

                              {
    return &partners_;
  }

void tesseract::TabVector::Print

(

const char *

prefix

)

Definition at line 526 of file tabvector.cpp.

                                        {
  if (this == NULL) {
    tprintf("%s <null>\n", prefix);
  } else {
    tprintf("%s %s (%d,%d)->(%d,%d) w=%d s=%d, sort key=%d, boxes=%d,"
            " partners=%d\n",
            prefix, kAlignmentNames[alignment_],
            startpt_.x(), startpt_.y(), endpt_.x(), endpt_.y(),
            mean_width_, percent_score_, sort_key_,
            boxes_.length(), partners_.length());
  }
}

void tesseract::TabVector::ReflectInYAxis

(

)

[inline]

Definition at line 265 of file tabvector.h.

                        {
    startpt_.set_x(-startpt_.x());
    endpt_.set_x(-endpt_.x());
    sort_key_ = -sort_key_;
    if (alignment_ == TA_LEFT_ALIGNED)
      alignment_ = TA_RIGHT_ALIGNED;
    else if (alignment_ == TA_RIGHT_ALIGNED)
      alignment_ = TA_LEFT_ALIGNED;
    if (alignment_ == TA_LEFT_RAGGED)
      alignment_ = TA_RIGHT_RAGGED;
    else if (alignment_ == TA_RIGHT_RAGGED)
      alignment_ = TA_LEFT_RAGGED;
  }

void tesseract::TabVector::Rotate

(

const FCOORD &

rotation

)

Definition at line 282 of file tabvector.cpp.

                                             {
  startpt_.rotate(rotation);
  endpt_.rotate(rotation);
  int dx = endpt_.x() - startpt_.x();
  int dy = endpt_.y() - startpt_.y();
  if ((dy < 0 && abs(dy) > abs(dx)) || (dx < 0 && abs(dx) > abs(dy))) {
    // Need to flip start/end.
    ICOORD tmp = startpt_;
    startpt_ = endpt_;
    endpt_ = tmp;
  }
}

void tesseract::TabVector::set_bottom_constraints

(

TabConstraint_LIST *

constraints

)

[inline]

Definition at line 167 of file tabvector.h.

                                                               {
    bottom_constraints_ = constraints;
  }

void tesseract::TabVector::set_endpt

(

const ICOORD &

end

)

[inline]

Definition at line 176 of file tabvector.h.

                                    {
    endpt_ = end;
  }

void tesseract::TabVector::set_intersects_other_lines

(

bool

value

)

[inline]

Definition at line 182 of file tabvector.h.

                                              {
    intersects_other_lines_ = value;
  }

void tesseract::TabVector::set_startpt

(

const ICOORD &

start

)

[inline]

Definition at line 173 of file tabvector.h.

                                        {
    startpt_ = start;
  }

void tesseract::TabVector::set_top_constraints

(

TabConstraint_LIST *

constraints

)

[inline]

Definition at line 164 of file tabvector.h.

                                                            {
    top_constraints_ = constraints;
  }

void tesseract::TabVector::SetupConstraints

(

)

Definition at line 297 of file tabvector.cpp.

                                 {
  TabConstraint::CreateConstraint(this, false);
  TabConstraint::CreateConstraint(this, true);
}

void tesseract::TabVector::SetupPartnerConstraints

(

)

Definition at line 303 of file tabvector.cpp.

                                        {
  // With the first and last partner, we want a common bottom and top,
  // respectively, and for each change of partner, we want a common
  // top of first with bottom of next.
  TabVector_C_IT it(&partners_);
  TabVector* prev_partner = NULL;
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    TabVector* partner = it.data();
    if (partner->top_constraints_ == NULL ||
        partner->bottom_constraints_ == NULL) {
      partner->Print("Impossible: has no constraints");
      Print("This vector has it as a partner");
      continue;
    }
    if (prev_partner == NULL) {
      // This is the first partner, so common bottom.
      if (TabConstraint::CompatibleConstraints(bottom_constraints_,
                                               partner->bottom_constraints_))
        TabConstraint::MergeConstraints(bottom_constraints_,
                                        partner->bottom_constraints_);
    } else {
      // We need prev top to be common with partner bottom.
      if (TabConstraint::CompatibleConstraints(prev_partner->top_constraints_,
                                               partner->bottom_constraints_))
        TabConstraint::MergeConstraints(prev_partner->top_constraints_,
                                        partner->bottom_constraints_);
    }
    prev_partner = partner;
    if (it.at_last()) {
      // This is the last partner, so common top.
      if (TabConstraint::CompatibleConstraints(top_constraints_,
                                               partner->top_constraints_))
        TabConstraint::MergeConstraints(top_constraints_,
                                        partner->top_constraints_);
    }
  }
}

void tesseract::TabVector::SetupPartnerConstraints

(

TabVector *

partner

)

Definition at line 342 of file tabvector.cpp.

                                                          {
  if (TabConstraint::CompatibleConstraints(bottom_constraints_,
                                           partner->bottom_constraints_))
    TabConstraint::MergeConstraints(bottom_constraints_,
                                    partner->bottom_constraints_);
  if (TabConstraint::CompatibleConstraints(top_constraints_,
                                           partner->top_constraints_))
    TabConstraint::MergeConstraints(top_constraints_,
                                    partner->top_constraints_);
}

void tesseract::TabVector::SetYEnd

(

int

end_y

)

Definition at line 276 of file tabvector.cpp.

                                 {
  endpt_.set_x(XAtY(end_y));
  endpt_.set_y(end_y);
}

void tesseract::TabVector::SetYStart

(

int

start_y

)

Definition at line 271 of file tabvector.cpp.

                                     {
  startpt_.set_x(XAtY(start_y));
  startpt_.set_y(start_y);
}

TabVector * tesseract::TabVector::ShallowCopy

(

)

const

Definition at line 234 of file tabvector.cpp.

                                        {
  TabVector* copy = new TabVector();
  copy->startpt_ = startpt_;
  copy->endpt_ = endpt_;
  copy->alignment_ = alignment_;
  copy->extended_ymax_ = extended_ymax_;
  copy->extended_ymin_ = extended_ymin_;
  copy->intersects_other_lines_ = intersects_other_lines_;
  return copy;
}

bool tesseract::TabVector::SimilarTo	(	const ICOORD &	vertical,
		const TabVector &	other,
		BlobGrid *	grid
	)		const

Definition at line 395 of file tabvector.cpp.

                                                                        {
  if ((IsRightTab() && other.IsRightTab()) ||
      (IsLeftTab() && other.IsLeftTab())) {
    // If they don't overlap, at least in extensions, then there is no chance.
    if (ExtendedOverlap(other.extended_ymax_, other.extended_ymin_) < 0)
      return false;
    // A fast approximation to the scale factor of the sort_key_.
    int v_scale = abs(vertical.y());
    if (v_scale == 0)
      v_scale = 1;
    // If they are close enough, then OK.
    if (sort_key_ + kSimilarVectorDist * v_scale >= other.sort_key_ &&
        sort_key_ - kSimilarVectorDist * v_scale <= other.sort_key_)
      return true;
    // Ragged tabs get a bigger threshold.
    if (!IsRagged() || !other.IsRagged() ||
        sort_key_ + kSimilarRaggedDist * v_scale < other.sort_key_ ||
        sort_key_ - kSimilarRaggedDist * v_scale > other.sort_key_)
      return false;
    if (grid == NULL) {
      // There is nothing else to test!
      return true;
    }
    // If there is nothing in the rectangle between the vector that is going to
    // move, and the place it is moving to, then they can be merged.
    // Setup a vertical search for any blob.
    const TabVector* mover = (IsRightTab() &&
       sort_key_ < other.sort_key_) ? this : &other;
    int top_y = mover->endpt_.y();
    int bottom_y = mover->startpt_.y();
    int left = MIN(mover->XAtY(top_y), mover->XAtY(bottom_y));
    int right = MAX(mover->XAtY(top_y), mover->XAtY(bottom_y));
    int shift = abs(sort_key_ - other.sort_key_) / v_scale;
    if (IsRightTab()) {
      right += shift;
    } else {
      left -= shift;
    }

    GridSearch<BLOBNBOX, BLOBNBOX_CLIST, BLOBNBOX_C_IT> vsearch(grid);
    vsearch.StartVerticalSearch(left, right, top_y);
    BLOBNBOX* blob;
    while ((blob = vsearch.NextVerticalSearch(true)) != NULL) {
      TBOX box = blob->bounding_box();
      if (box.top() > bottom_y)
        return true;  // Nothing found.
      if (box.bottom() < top_y)
        continue;  // Doesn't overlap.
      int left_at_box = XAtY(box.bottom());
      int right_at_box = left_at_box;
      if (IsRightTab())
        right_at_box += shift;
      else
        left_at_box -= shift;
      if (MIN(right_at_box, box.right()) > MAX(left_at_box, box.left()))
        return false;
    }
    return true;  // Nothing found.
  }
  return false;
}

int tesseract::TabVector::sort_key

(

)

const [inline]

Definition at line 158 of file tabvector.h.

                       {
    return sort_key_;
  }

static int tesseract::TabVector::SortKey	(	const ICOORD &	vertical,
		int	x,
		int	y
	)		[inline, static]

Definition at line 280 of file tabvector.h.

                                                           {
    ICOORD pt(x, y);
    return pt * vertical;
  }

static int tesseract::TabVector::SortVectorsByKey	(	const void *	v1,
		const void *	v2
	)		[inline, static]

Definition at line 294 of file tabvector.h.

                                                              {
    const TabVector* tv1 = *reinterpret_cast<const TabVector* const *>(v1);
    const TabVector* tv2 = *reinterpret_cast<const TabVector* const *>(v2);
    return tv1->sort_key_ - tv2->sort_key_;
  }

const ICOORD& tesseract::TabVector::startpt

(

)

const [inline]

Definition at line 146 of file tabvector.h.

                                {
    return startpt_;
  }

TabVector * tesseract::TabVector::VerticalTextlinePartner

(

)

Definition at line 889 of file tabvector.cpp.

                                              {
  if (!partners_.singleton())
    return NULL;
  TabVector_C_IT partner_it(&partners_);
  TabVector* partner = partner_it.data();
  BLOBNBOX_C_IT box_it1(&boxes_);
  BLOBNBOX_C_IT box_it2(&partner->boxes_);
  // Count how many boxes are also in the other list.
  // At the same time, gather the mean width and median vertical gap.
  if (textord_debug_tabfind > 1) {
    Print("Testing for vertical text");
    partner->Print("           partner");
  }
  int num_matched = 0;
  int num_unmatched = 0;
  int total_widths = 0;
  int width = startpt().x() - partner->startpt().x();
  if (width < 0)
    width = -width;
  STATS gaps(0, width * 2);
  BLOBNBOX* prev_bbox = NULL;
  box_it2.mark_cycle_pt();
  for (box_it1.mark_cycle_pt(); !box_it1.cycled_list(); box_it1.forward()) {
    BLOBNBOX* bbox = box_it1.data();
    TBOX box = bbox->bounding_box();
    if (prev_bbox != NULL) {
      gaps.add(box.bottom() - prev_bbox->bounding_box().top(), 1);
    }
    while (!box_it2.cycled_list() && box_it2.data() != bbox &&
           box_it2.data()->bounding_box().bottom() < box.bottom()) {
      box_it2.forward();
    }
    if (!box_it2.cycled_list() && box_it2.data() == bbox &&
        bbox->region_type() >= BRT_UNKNOWN &&
        (prev_bbox == NULL || prev_bbox->region_type() >= BRT_UNKNOWN))
      ++num_matched;
    else
      ++num_unmatched;
    total_widths += box.width();
    prev_bbox = bbox;
  }
  double avg_width = total_widths * 1.0 / (num_unmatched + num_matched);
  double max_gap = textord_tabvector_vertical_gap_fraction * avg_width;
  int min_box_match = static_cast<int>((num_matched + num_unmatched) *
                                       textord_tabvector_vertical_box_ratio);
  bool is_vertical = (gaps.get_total() > 0 &&
                      num_matched >= min_box_match &&
                      gaps.median() <= max_gap);
  if (textord_debug_tabfind > 1) {
    tprintf("gaps=%d, matched=%d, unmatched=%d, min_match=%d "
            "median gap=%.2f, width=%.2f max_gap=%.2f Vertical=%s\n",
            gaps.get_total(), num_matched, num_unmatched, min_box_match,
            gaps.median(), avg_width, max_gap, is_vertical?"Yes":"No");
  }
  return (is_vertical) ? partner : NULL;
}

int tesseract::TabVector::VOverlap

(

const TabVector &

other

)

const [inline]

Definition at line 199 of file tabvector.h.

                                             {
    return MIN(other.endpt_.y(), endpt_.y()) -
           MAX(other.startpt_.y(), startpt_.y());
  }

int tesseract::TabVector::VOverlap	(	int	top_y,
		int	bottom_y
	)		const [inline]

Definition at line 204 of file tabvector.h.

                                              {
    return MIN(top_y, endpt_.y()) - MAX(bottom_y, startpt_.y());
  }

int tesseract::TabVector::XAtY

(

int

y

)

const [inline]

Definition at line 189 of file tabvector.h.

                        {
    int height = endpt_.y() - startpt_.y();
    if (height != 0)
      return (y - startpt_.y()) * (endpt_.x() - startpt_.x()) / height +
             startpt_.x();
    else
      return startpt_.x();
  }

static int tesseract::TabVector::XAtY	(	const ICOORD &	vertical,
		int	sort_key,
		int	y
	)		[inline, static]

Definition at line 286 of file tabvector.h.

                                                               {
    if (vertical.y() != 0)
      return (vertical.x() * y + sort_key) / vertical.y();
    else
      return sort_key;
  }

void tesseract::TabVector::XYFlip

(

)

[inline]

Definition at line 255 of file tabvector.h.

                {
    int x = startpt_.y();
    startpt_.set_y(startpt_.x());
    startpt_.set_x(x);
    x = endpt_.y();
    endpt_.set_y(endpt_.x());
    endpt_.set_x(x);
  }

---

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

• tesseract-ocr/textord/tabvector.h
• tesseract-ocr/textord/tabvector.cpp