findseam.cpp

来自「一个google的OCR源码」· C++ 代码 · 共 567 行 · 第 1/2 页

      dist < SPLIT_CLOSENESS &&
    seam->priority + this_one->priority < ok_split) {
      inT16 split1_point1_y = this_one->split1->point1->pos.y;
      inT16 split1_point2_y = this_one->split1->point2->pos.y;
      inT16 split2_point1_y = 0;
      inT16 split2_point2_y = 0;
      if (this_one->split2) {
        split2_point1_y = this_one->split2->point1->pos.y;
        split2_point2_y = this_one->split2->point2->pos.y;
      }
      if (
        /*!tessedit_fix_sideways_chops || */
        (
          /* this_one->split1 always exists */
          (
            ((split1_point1_y >= top1 && split1_point2_y >= top1) ||
             (split1_point1_y <= bottom1 && split1_point2_y <= bottom1))
            &&
            ((split1_point1_y >= top2 && split1_point2_y >= top2) ||
             (split1_point1_y <= bottom2 && split1_point2_y <= bottom2))
          )
        )
        &&
        (
          this_one->split2 == NULL ||
          (
            ((split2_point1_y >= top1 && split2_point2_y >= top1) ||
             (split2_point1_y <= bottom1 && split2_point2_y <= bottom1))
            &&
            ((split2_point1_y >= top2 && split2_point2_y >= top2) ||
             (split2_point1_y <= bottom2 && split2_point2_y <= bottom2))
          )
        )
      ) {
        new_one = join_two_seams (seam, this_one);
        if (chop_debug > 1)
          print_seam ("Combo priority       ", new_one);
        add_seam_to_queue (seam_queue, new_one, new_one->priority);
      }
    }
  }
}


/**********************************************************************
 * constrained_split
 *
 * Constrain this split to obey certain rules.  It must not cross any
 * inner outline.  It must not cut off a small chunk of the outline.
 **********************************************************************/
inT16 constrained_split(SPLIT *split, TBLOB *blob) {
  TESSLINE *outline;

  if (is_little_chunk (split->point1, split->point2))
    return (FALSE);

  for (outline = blob->outlines; outline; outline = outline->next) {
    if (split_bounds_overlap (split, outline) &&
    crosses_outline (split->point1, split->point2, outline->loop)) {
      return (FALSE);
    }
  }
  return (TRUE);
}


/**********************************************************************
 * delete_seam_pile
 *
 * Delete the seams that are held in the seam pile.  Destroy the splits
 * that are referenced by these seams.
 **********************************************************************/
void delete_seam_pile(SEAM_PILE seam_pile) {
  inT16 x;

  array_loop(seam_pile, x) {
    delete_seam ((SEAM *) array_value (seam_pile, x));
  }
  array_free(seam_pile);
}


/**********************************************************************
 * pick_good_seam
 *
 * Find and return a good seam that will split this blob into two pieces.
 * Work from the outlines provided.
 **********************************************************************/
SEAM *pick_good_seam(TBLOB *blob) {
  SEAM_QUEUE seam_queue;
  SEAM_PILE seam_pile;
  POINT_GROUP point_heap;
  PRIORITY priority;
  EDGEPT *edge;
  EDGEPT *points[MAX_NUM_POINTS];
  SEAM *seam = NULL;
  TESSLINE *outline;
  inT16 num_points = 0;

#ifndef GRAPHICS_DISABLED
  if (chop_debug > 2)
    display_splits = TRUE;

  draw_blob_edges(blob);
#endif

  point_heap = MakeHeap (MAX_NUM_POINTS);
  for (outline = blob->outlines; outline; outline = outline->next)
    prioritize_points(outline, point_heap);

  while (HeapPop (point_heap, &priority, &edge) == OK) {
    if (num_points < MAX_NUM_POINTS)
      points[num_points++] = (EDGEPT *) edge;
  }
  FreeHeap(point_heap);

  /* Initialize queue & pile */
  create_seam_pile(seam_pile);
  create_seam_queue(seam_queue);

  try_point_pairs(points, num_points, seam_queue, &seam_pile, &seam, blob);

  try_vertical_splits(points, num_points, seam_queue, &seam_pile, &seam, blob);

  if (seam == NULL) {
    choose_best_seam(seam_queue, &seam_pile, NULL, BAD_PRIORITY, &seam, blob);
  }
  else if (seam->priority > good_split) {
    choose_best_seam (seam_queue, &seam_pile, NULL, seam->priority,
      &seam, blob);
  }
  delete_seam_queue(seam_queue);
  delete_seam_pile(seam_pile);

  if (seam) {
    if (seam->priority > ok_split) {
      delete_seam(seam);
      seam = NULL;
    }
#ifndef GRAPHICS_DISABLED
    else if (display_splits) {
      if (seam->split1)
        mark_split (seam->split1);
      if (seam->split2)
        mark_split (seam->split2);
      if (seam->split3)
        mark_split (seam->split3);
      if (chop_debug > 2) {
        update_edge_window();
        edge_window_wait();
      }
    }
#endif
  }

  if (chop_debug)
    display_splits = FALSE;

  return (seam);
}


/**********************************************************************
 * seam_priority
 *
 * Assign a full priority value to the seam.
 **********************************************************************/
PRIORITY seam_priority(SEAM *seam, inT16 xmin, inT16 xmax) {
  PRIORITY priority;

  if (seam->split1 == NULL)
    priority = 0;

  else if (seam->split2 == NULL) {
    priority = (seam->priority +
      full_split_priority (seam->split1, xmin, xmax));
  }

  else if (seam->split3 == NULL) {
    split_outline (seam->split2->point1, seam->split2->point2);
    priority = (seam->priority +
      full_split_priority (seam->split1, xmin, xmax));
    unsplit_outlines (seam->split2->point1, seam->split2->point2);
  }

  else {
    split_outline (seam->split2->point1, seam->split2->point2);
    split_outline (seam->split3->point1, seam->split3->point2);
    priority = (seam->priority +
      full_split_priority (seam->split1, xmin, xmax));
    unsplit_outlines (seam->split3->point1, seam->split3->point2);
    unsplit_outlines (seam->split2->point1, seam->split2->point2);
  }

  return (priority);
}


/**********************************************************************
 * try_point_pairs
 *
 * Try all the splits that are produced by pairing critical points
 * together.  See if any of them are suitable for use.  Use a seam
 * queue and seam pile that have already been initialized and used.
 **********************************************************************/
void
try_point_pairs (EDGEPT * points[MAX_NUM_POINTS],
inT16 num_points,
SEAM_QUEUE seam_queue,
SEAM_PILE * seam_pile, SEAM ** seam, TBLOB * blob) {
  inT16 x;
  inT16 y;
  SPLIT *split;
  PRIORITY priority;

  for (x = 0; x < num_points; x++) {
    for (y = x + 1; y < num_points; y++) {

      if (points[y] &&
        weighted_edgept_dist (points[x], points[y],
        x_y_weight) < split_length &&
        points[x] != points[y]->next &&
        points[y] != points[x]->next &&
        !is_exterior_point (points[x], points[y]) &&
      !is_exterior_point (points[y], points[x])) {

        split = new_split (points[x], points[y]);
        priority = partial_split_priority (split);

        choose_best_seam(seam_queue, seam_pile, split, priority, seam, blob);

        if (*seam && (*seam)->priority < good_split)
          return;
      }
    }
  }

}


/**********************************************************************
 * try_vertical_splits
 *
 * Try all the splits that are produced by vertical projection to see
 * if any of them are suitable for use.  Use a seam queue and seam pile
 * that have already been initialized and used.
 **********************************************************************/
void
try_vertical_splits (EDGEPT * points[MAX_NUM_POINTS],
inT16 num_points,
SEAM_QUEUE seam_queue,
SEAM_PILE * seam_pile, SEAM ** seam, TBLOB * blob) {
  EDGEPT *vertical_point = NULL;
  SPLIT *split;
  inT16 x;
  PRIORITY priority;
  TESSLINE *outline;

  for (x = 0; x < num_points; x++) {

    if (*seam != NULL && (*seam)->priority < good_split)
      return;

    vertical_point = NULL;
    for (outline = blob->outlines; outline; outline = outline->next) {
      vertical_projection_point (points[x],
        outline->loop, &vertical_point);
    }

    if (vertical_point &&
      points[x] != vertical_point->next &&
      vertical_point != points[x]->next &&
      weighted_edgept_dist (points[x], vertical_point,
    x_y_weight) < split_length) {

      split = new_split (points[x], vertical_point);
      priority = partial_split_priority (split);

      choose_best_seam(seam_queue, seam_pile, split, priority, seam, blob);
    }
  }
}