tesseract-ocr/ccstruct/werd.cpp

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/**********************************************************************
 * File:        werd.cpp  (Formerly word.c)
 * Description: Code for the WERD class.
 * Author:      Ray Smith
 * Created:     Tue Oct 08 14:32:12 BST 1991
 *
 * (C) Copyright 1991, Hewlett-Packard Ltd.
 ** Licensed under the Apache License, Version 2.0 (the "License");
 ** you may not use this file except in compliance with the License.
 ** You may obtain a copy of the License at
 ** http://www.apache.org/licenses/LICENSE-2.0
 ** Unless required by applicable law or agreed to in writing, software
 ** distributed under the License is distributed on an "AS IS" BASIS,
 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 ** See the License for the specific language governing permissions and
 ** limitations under the License.
 *
 **********************************************************************/

#include "mfcpch.h"
#include "blckerr.h"
#include "helpers.h"
#include "linlsq.h"
#include "werd.h"

#define FIRST_COLOUR    ScrollView::RED         //< first rainbow colour
#define LAST_COLOUR     ScrollView::AQUAMARINE  //< last rainbow colour
#define CHILD_COLOUR    ScrollView::BROWN       //< colour of children

const ERRCODE CANT_SCALE_EDGESTEPS =
    "Attempted to scale an edgestep format word";

ELIST2IZE(WERD)


WERD::WERD(C_BLOB_LIST *blob_list, uinT8 blank_count, const char *text)
  : blanks(blank_count),
    flags(0),
    script_id_(0),
    correct(text) {
  C_BLOB_IT start_it = blob_list;
  C_BLOB_IT end_it = blob_list;
  C_BLOB_IT rej_cblob_it = &rej_cblobs;
  C_OUTLINE_IT c_outline_it;
  inT16 inverted_vote = 0;
  inT16 non_inverted_vote = 0;

  // Move blob_list's elements into cblobs.
  while (!end_it.at_last())
    end_it.forward();
  cblobs.assign_to_sublist(&start_it, &end_it);

  /*
    Set white on black flag for the WERD, moving any duff blobs onto the
    rej_cblobs list.
    First, walk the cblobs checking the inverse flag for each outline of each
    cblob. If a cblob has inconsistent flag settings for its different
    outlines, move the blob to the reject list. Otherwise, increment the
    appropriate w-on-b or b-on-w vote for the word.

    Now set the inversion flag for the WERD by maximum vote.

    Walk the blobs again, moving any blob whose inversion flag does not agree
    with the concencus onto the reject list.
  */
  start_it.set_to_list(&cblobs);
  if (start_it.empty())
    return;
  for (start_it.mark_cycle_pt(); !start_it.cycled_list(); start_it.forward()) {
    BOOL8 reject_blob = FALSE;
    BOOL8 blob_inverted;

    c_outline_it.set_to_list(start_it.data()->out_list());
    blob_inverted = c_outline_it.data()->flag(COUT_INVERSE);
    for (c_outline_it.mark_cycle_pt();
         !c_outline_it.cycled_list() && !reject_blob;
         c_outline_it.forward()) {
      reject_blob = c_outline_it.data()->flag(COUT_INVERSE) != blob_inverted;
    }
    if (reject_blob) {
      rej_cblob_it.add_after_then_move(start_it.extract());
    } else {
      if (blob_inverted)
        inverted_vote++;
      else
        non_inverted_vote++;
    }
  }

  flags.set_bit(W_INVERSE, (inverted_vote > non_inverted_vote));

  start_it.set_to_list(&cblobs);
  if (start_it.empty())
    return;
  for (start_it.mark_cycle_pt(); !start_it.cycled_list(); start_it.forward()) {
    c_outline_it.set_to_list(start_it.data()->out_list());
    if (c_outline_it.data()->flag(COUT_INVERSE) != flags.bit(W_INVERSE))
      rej_cblob_it.add_after_then_move(start_it.extract());
  }
}


WERD::WERD(C_BLOB_LIST * blob_list,         //< In word order
           WERD * clone)                    //< Source of flags
  : flags(clone->flags),
    script_id_(clone->script_id_),
    correct(clone->correct) {
  C_BLOB_IT start_it = blob_list;  // iterator
  C_BLOB_IT end_it = blob_list;    // another

  while (!end_it.at_last ())
    end_it.forward ();           //move to last
  ((C_BLOB_LIST *) (&cblobs))->assign_to_sublist (&start_it, &end_it);
  //move to our list
  blanks = clone->blanks;
  //      fprintf(stderr,"Wrong constructor!!!!\n");
}

// Construct a WERD from a single_blob and clone the flags from this.
// W_BOL and W_EOL flags are set according to the given values.
WERD* WERD::ConstructFromSingleBlob(bool bol, bool eol, C_BLOB* blob) {
  C_BLOB_LIST temp_blobs;
  C_BLOB_IT temp_it(&temp_blobs);
  temp_it.add_after_then_move(blob);
  WERD* blob_word = new WERD(&temp_blobs, this);
  blob_word->set_flag(W_BOL, bol);
  blob_word->set_flag(W_EOL, eol);
  return blob_word;
}

TBOX WERD::bounding_box() {
  TBOX box;                       // box being built
  C_BLOB_IT rej_cblob_it = &rej_cblobs;  // rejected blobs

  for (rej_cblob_it.mark_cycle_pt(); !rej_cblob_it.cycled_list();
       rej_cblob_it.forward()) {
    box += rej_cblob_it.data()->bounding_box();
  }

  C_BLOB_IT it = &cblobs;    // blobs of WERD
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    box += it.data()->bounding_box();
  }
  return box;
}


void WERD::move(const ICOORD vec) {
  C_BLOB_IT cblob_it(&cblobs);  // cblob iterator

  for (cblob_it.mark_cycle_pt(); !cblob_it.cycled_list(); cblob_it.forward())
    cblob_it.data()->move(vec);
}

void WERD::join_on(WERD* other) {
  C_BLOB_IT blob_it(&cblobs);
  C_BLOB_IT src_it(&other->cblobs);
  C_BLOB_IT rej_cblob_it(&rej_cblobs);
  C_BLOB_IT src_rej_it(&other->rej_cblobs);

  while (!src_it.empty()) {
    blob_it.add_to_end(src_it.extract());
    src_it.forward();
  }
  while (!src_rej_it.empty()) {
    rej_cblob_it.add_to_end(src_rej_it.extract());
    src_rej_it.forward();
  }
}


void WERD::copy_on(WERD* other) {
  bool reversed = other->bounding_box().left() < bounding_box().left();
  C_BLOB_IT c_blob_it(&cblobs);
  C_BLOB_LIST c_blobs;

  c_blobs.deep_copy(&other->cblobs, &C_BLOB::deep_copy);
  if (reversed) {
    c_blob_it.add_list_before(&c_blobs);
  } else {
    c_blob_it.move_to_last();
    c_blob_it.add_list_after(&c_blobs);
  }
  if (!other->rej_cblobs.empty()) {
    C_BLOB_IT rej_c_blob_it(&rej_cblobs);
    C_BLOB_LIST new_rej_c_blobs;

    new_rej_c_blobs.deep_copy(&other->rej_cblobs, &C_BLOB::deep_copy);
    if (reversed) {
      rej_c_blob_it.add_list_before(&new_rej_c_blobs);
    } else {
      rej_c_blob_it.move_to_last();
      rej_c_blob_it.add_list_after(&new_rej_c_blobs);
    }
  }
}

void WERD::print() {
  tprintf("Blanks= %d\n", blanks);
  bounding_box().print();
  tprintf("Flags = %d = 0%o\n", flags.val, flags.val);
  tprintf("   W_SEGMENTED = %s\n", flags.bit(W_SEGMENTED) ? "TRUE" : "FALSE ");
  tprintf("   W_ITALIC = %s\n", flags.bit(W_ITALIC) ? "TRUE" : "FALSE ");
  tprintf("   W_BOL = %s\n", flags.bit(W_BOL) ? "TRUE" : "FALSE ");
  tprintf("   W_EOL = %s\n", flags.bit(W_EOL) ? "TRUE" : "FALSE ");
  tprintf("   W_NORMALIZED = %s\n",
          flags.bit(W_NORMALIZED) ? "TRUE" : "FALSE ");
  tprintf("   W_SCRIPT_HAS_XHEIGHT = %s\n",
          flags.bit(W_SCRIPT_HAS_XHEIGHT) ? "TRUE" : "FALSE ");
  tprintf("   W_SCRIPT_IS_LATIN = %s\n",
          flags.bit(W_SCRIPT_IS_LATIN) ? "TRUE" : "FALSE ");
  tprintf("   W_DONT_CHOP = %s\n", flags.bit(W_DONT_CHOP) ? "TRUE" : "FALSE ");
  tprintf("   W_REP_CHAR = %s\n", flags.bit(W_REP_CHAR) ? "TRUE" : "FALSE ");
  tprintf("   W_FUZZY_SP = %s\n", flags.bit(W_FUZZY_SP) ? "TRUE" : "FALSE ");
  tprintf("   W_FUZZY_NON = %s\n", flags.bit(W_FUZZY_NON) ? "TRUE" : "FALSE ");
  tprintf("Correct= %s\n", correct.string());
  tprintf("Rejected cblob count = %d\n", rej_cblobs.length());
  tprintf("Script = %d\n", script_id_);
}


#ifndef GRAPHICS_DISABLED
void WERD::plot(ScrollView *window, ScrollView::Color colour) {
  C_BLOB_IT it = &cblobs;
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    it.data()->plot(window, colour, colour);
  }
  plot_rej_blobs(window);
}
#endif  // GRAPHICS_DISABLED

// Get the next color in the (looping) rainbow.
ScrollView::Color WERD::NextColor(ScrollView::Color colour) {
  ScrollView::Color next = static_cast<ScrollView::Color>(colour + 1);
  if (next >= LAST_COLOUR || next < FIRST_COLOUR)
    next = FIRST_COLOUR;
  return next;
}

#ifndef GRAPHICS_DISABLED

void WERD::plot(ScrollView* window) {
  ScrollView::Color colour = FIRST_COLOUR;
  C_BLOB_IT it = &cblobs;
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    it.data()->plot(window, colour, CHILD_COLOUR);
    colour = NextColor(colour);
  }
  plot_rej_blobs(window);
}


void WERD::plot_rej_blobs(ScrollView *window) {
  C_BLOB_IT it = &rej_cblobs;
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    it.data()->plot(window, ScrollView::GREY, ScrollView::GREY);
  }
}
#endif  // GRAPHICS_DISABLED


WERD *WERD::shallow_copy() {
  WERD *new_word = new WERD;

  new_word->blanks = blanks;
  new_word->flags = flags;
  new_word->dummy = dummy;
  new_word->correct = correct;
  return new_word;
}


WERD & WERD::operator= (const WERD & source) {
  this->ELIST2_LINK::operator= (source);
  blanks = source.blanks;
  flags = source.flags;
  script_id_ = source.script_id_;
  dummy = source.dummy;
  correct = source.correct;
  if (!cblobs.empty())
    cblobs.clear();
  cblobs.deep_copy(&source.cblobs, &C_BLOB::deep_copy);

  if (!rej_cblobs.empty())
    rej_cblobs.clear();
  rej_cblobs.deep_copy(&source.rej_cblobs, &C_BLOB::deep_copy);
  return *this;
}


int word_comparator(const void *word1p, const void *word2p) {
  WERD *word1 = *(WERD **)word1p;
  WERD *word2 = *(WERD **)word2p;
  return word1->bounding_box().left() - word2->bounding_box().left();
}

WERD* WERD::ConstructWerdWithNewBlobs(C_BLOB_LIST* all_blobs,
                                      C_BLOB_LIST* orphan_blobs) {
  C_BLOB_LIST current_blob_list;
  C_BLOB_IT werd_blobs_it(&current_blob_list);
  // Add the word's c_blobs.
  werd_blobs_it.add_list_after(cblob_list());

  // New blob list. These contain the blobs which will form the new word.
  C_BLOB_LIST new_werd_blobs;
  C_BLOB_IT new_blobs_it(&new_werd_blobs);

  // not_found_blobs contains the list of current word's blobs for which a
  // corresponding blob wasn't found in the input all_blobs list.
  C_BLOB_LIST not_found_blobs;
  C_BLOB_IT not_found_it(&not_found_blobs);
  not_found_it.move_to_last();

  werd_blobs_it.move_to_first();
  for (werd_blobs_it.mark_cycle_pt(); !werd_blobs_it.cycled_list();
       werd_blobs_it.forward()) {
    C_BLOB* werd_blob = werd_blobs_it.extract();
    TBOX werd_blob_box = werd_blob->bounding_box();
    bool found = false;
    // Now find the corresponding blob for this blob in the all_blobs
    // list. For now, follow the inefficient method of pairwise
    // comparisons. Ideally, one can pre-bucket the blobs by row.
    C_BLOB_IT all_blobs_it(all_blobs);
    for (all_blobs_it.mark_cycle_pt(); !all_blobs_it.cycled_list();
         all_blobs_it.forward()) {
      C_BLOB* a_blob = all_blobs_it.data();
      // Compute the overlap of the two blobs. If major, a_blob should
      // be added to the new blobs list.
      TBOX a_blob_box = a_blob->bounding_box();
      if (a_blob_box.null_box()) {
        tprintf("Bounding box couldn't be ascertained\n");
      }
      if (werd_blob_box.contains(a_blob_box) ||
          werd_blob_box.major_overlap(a_blob_box)) {
        // Old blobs are from minimal splits, therefore are expected to be
        // bigger. The new small blobs should cover a significant portion.
        // This is it.
        all_blobs_it.extract();
        new_blobs_it.add_after_then_move(a_blob);
        found = true;
      }
    }
    if (!found) {
      not_found_it.add_after_then_move(werd_blob);
    } else {
      delete werd_blob;
    }
  }
  // Iterate over all not found blobs. Some of them may be due to
  // under-segmentation (which is OK, since the corresponding blob is already
  // in the list in that case.
  not_found_it.move_to_first();
  for (not_found_it.mark_cycle_pt(); !not_found_it.cycled_list();
       not_found_it.forward()) {
    C_BLOB* not_found = not_found_it.data();
    TBOX not_found_box = not_found->bounding_box();
    C_BLOB_IT existing_blobs_it(new_blobs_it);
    for (existing_blobs_it.mark_cycle_pt(); !existing_blobs_it.cycled_list();
         existing_blobs_it.forward()) {
      C_BLOB* a_blob = existing_blobs_it.data();
      TBOX a_blob_box = a_blob->bounding_box();
      if ((not_found_box.major_overlap(a_blob_box) ||
           a_blob_box.major_overlap(not_found_box)) &&
           not_found_box.y_overlap(a_blob_box)) {
        // Already taken care of.
        delete not_found_it.extract();
        break;
      }
    }
  }
  if (orphan_blobs) {
    C_BLOB_IT orphan_blobs_it(orphan_blobs);
    orphan_blobs_it.move_to_last();
    orphan_blobs_it.add_list_after(&not_found_blobs);
  }

  // New blobs are ready. Create a new werd object with these.
  WERD* new_werd = NULL;
  if (!new_werd_blobs.empty()) {
    new_werd = new WERD(&new_werd_blobs, this);
  } else {
    // Add the blobs back to this word so that it can be reused.
    C_BLOB_IT this_list_it(cblob_list());
    this_list_it.add_list_after(&not_found_blobs);
  }
  return new_werd;
}