/**********************************************************************

 * File:        tordmain.cpp  (Formerly textordp.c)

 * Description: C++ top level textord code.

 * Author:      Ray Smith

 *

 * (C) Copyright 1992, 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.

 *

 **********************************************************************/

#define _USE_MATH_DEFINES // for M_PI

#ifdef HAVE_CONFIG_H

#  include "config_auto.h"

#endif

#include "tordmain.h"

#include "blobbox.h"     // for BLOBNBOX_IT, BLOBNBOX, TO_BLOCK, TO_B...

#include "ccstruct.h"    // for CCStruct, CCStruct::kXHeightFraction

#include "clst.h"        // for CLISTIZE

#include "coutln.h"      // for C_OUTLINE_IT, C_OUTLINE_LIST, C_OUTLINE

#include "drawtord.h"    // for plot_box_list, to_win, create_to_win

#include "edgblob.h"     // for extract_edges

#include "errcode.h"     // for ASSERT_HOST, ...

#include "image.h"       // for Image, Leptonica (pixDestroy, pixGetHeight, ...)

#include "makerow.h"     // for textord_test_x, textord_test_y, texto...

#include "ocrblock.h"    // for BLOCK_IT, BLOCK, BLOCK_LIST (ptr only)

#include "ocrrow.h"      // for ROW, ROW_IT, ROW_LIST, tweak_row_base...

#include "params.h"      // for DoubleParam, BoolParam, IntParam

#include "pdblock.h"     // for PDBLK

#include "points.h"      // for FCOORD, ICOORD

#include "polyblk.h"     // for POLY_BLOCK

#include "quadratc.h"    // for QUAD_COEFFS

#include "quspline.h"    // for QSPLINE, tweak_row_baseline

#include "rect.h"        // for TBOX

#include "scrollview.h"  // for ScrollView, ScrollView::WHITE

#include "statistc.h"    // for STATS

#include "stepblob.h"    // for C_BLOB_IT, C_BLOB, C_BLOB_LIST

#include "textord.h"     // for Textord, WordWithBox, WordGrid, WordS...

#include "tprintf.h"     // for tprintf

#include "werd.h"        // for WERD_IT, WERD, WERD_LIST, W_DONT_CHOP

#include <cfloat>  // for FLT_MAX

#include <cmath>   // for ceil, floor, M_PI

#include <cstdint> // for INT16_MAX, uint32_t, int32_t, int16_t

#include <memory>

namespace tesseract {

#define MAX_NEAREST_DIST 600 // for block skew stats

/**********************************************************************

 * SetBlobStrokeWidth

 *

 * Set the horizontal and vertical stroke widths in the blob.

 **********************************************************************/

void SetBlobStrokeWidth(Image pix, BLOBNBOX *blob) {

  // Cut the blob rectangle into a Pix.

  int pix_height = pixGetHeight(pix);

  const TBOX &box = blob->bounding_box();

  int width = box.width();

  int height = box.height();

  Box *blob_pix_box = boxCreate(box.left(), pix_height - box.top(), width, height);

  Image pix_blob = pixClipRectangle(pix, blob_pix_box, nullptr);

  boxDestroy(&blob_pix_box);

  Image dist_pix = pixDistanceFunction(pix_blob, 4, 8, L_BOUNDARY_BG);

  pix_blob.destroy();

  // Compute the stroke widths.

  uint32_t *data = pixGetData(dist_pix);

  int wpl = pixGetWpl(dist_pix);

  // Horizontal width of stroke.

  STATS h_stats(0, width);

  for (int y = 0; y < height; ++y) {

    uint32_t *pixels = data + y * wpl;

    int prev_pixel = 0;

    int pixel = Image::getDataByte(pixels, 0);

    for (int x = 1; x < width; ++x) {

      int next_pixel = Image::getDataByte(pixels, x);

      // We are looking for a pixel that is equal to its vertical neighbours,

      // yet greater than its left neighbour.

      if (prev_pixel < pixel && (y == 0 || pixel == Image::getDataByte(pixels - wpl, x - 1)) &&

          (y == height - 1 || pixel == Image::getDataByte(pixels + wpl, x - 1))) {

        if (pixel > next_pixel) {

          // Single local max, so an odd width.

          h_stats.add(pixel * 2 - 1, 1);

        } else if (pixel == next_pixel && x + 1 < width && pixel > Image::getDataByte(pixels, x + 1)) {

          // Double local max, so an even width.

          h_stats.add(pixel * 2, 1);

        }

      }

      prev_pixel = pixel;

      pixel = next_pixel;

    }

  }

  // Vertical width of stroke.

  STATS v_stats(0, height);

  for (int x = 0; x < width; ++x) {

    int prev_pixel = 0;

    int pixel = Image::getDataByte(data, x);

    for (int y = 1; y < height; ++y) {

      uint32_t *pixels = data + y * wpl;

      int next_pixel = Image::getDataByte(pixels, x);

      // We are looking for a pixel that is equal to its horizontal neighbours,

      // yet greater than its upper neighbour.

      if (prev_pixel < pixel && (x == 0 || pixel == Image::getDataByte(pixels - wpl, x - 1)) &&

          (x == width - 1 || pixel == Image::getDataByte(pixels - wpl, x + 1))) {

        if (pixel > next_pixel) {

          // Single local max, so an odd width.

          v_stats.add(pixel * 2 - 1, 1);

        } else if (pixel == next_pixel && y + 1 < height &&

                   pixel > Image::getDataByte(pixels + wpl, x)) {

          // Double local max, so an even width.

          v_stats.add(pixel * 2, 1);

        }

      }

      prev_pixel = pixel;

      pixel = next_pixel;

    }

  }

  dist_pix.destroy();

  // Store the horizontal and vertical width in the blob, keeping both

  // widths if there is enough information, otherwise only the one with

  // the most samples.

  // If there are insufficient samples, store zero, rather than using

  // 2*area/perimeter, as the numbers that gives do not match the numbers

  // from the distance method.

  if (h_stats.get_total() >= (width + height) / 4) {

    blob->set_horz_stroke_width(h_stats.ile(0.5f));

    if (v_stats.get_total() >= (width + height) / 4) {

      blob->set_vert_stroke_width(v_stats.ile(0.5f));

    } else {

      blob->set_vert_stroke_width(0.0f);

    }

  } else {

    if (v_stats.get_total() >= (width + height) / 4 || v_stats.get_total() > h_stats.get_total()) {

      blob->set_horz_stroke_width(0.0f);

      blob->set_vert_stroke_width(v_stats.ile(0.5f));

    } else {

      blob->set_horz_stroke_width(h_stats.get_total() > 2 ? h_stats.ile(0.5f) : 0.0f);

      blob->set_vert_stroke_width(0.0f);

    }

  }

}

/**********************************************************************

 * assign_blobs_to_blocks2

 *

 * Make a list of TO_BLOCKs for portrait and landscape orientation.

 **********************************************************************/

void assign_blobs_to_blocks2(Image pix,

                             BLOCK_LIST *blocks,           // blocks to process

                             TO_BLOCK_LIST *port_blocks) { // output list

  BLOCK_IT block_it = blocks;

  C_BLOB_IT blob_it;       // iterator

  BLOBNBOX_IT port_box_it; // iterator

                           // destination iterator

  TO_BLOCK_IT port_block_it = port_blocks;

  for (block_it.mark_cycle_pt(); !block_it.cycled_list(); block_it.forward()) {

    auto block = block_it.data();

    auto port_block = new TO_BLOCK(block);

    // Convert the good outlines to block->blob_list

    port_box_it.set_to_list(&port_block->blobs);

    blob_it.set_to_list(block->blob_list());

    for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {

      auto blob = blob_it.extract();

      auto newblob = new BLOBNBOX(blob); // Convert blob to BLOBNBOX.

      newblob->set_owns_cblob(true);

      SetBlobStrokeWidth(pix, newblob);

      port_box_it.add_after_then_move(newblob);

    }

    // Put the rejected outlines in block->noise_blobs, which allows them to

    // be reconsidered and sorted back into rows and recover outlines mistakenly

    // rejected.

    port_box_it.set_to_list(&port_block->noise_blobs);

    blob_it.set_to_list(block->reject_blobs());

    for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {

      auto blob = blob_it.extract();

      auto newblob = new BLOBNBOX(blob); // Convert blob to BLOBNBOX.

      newblob->set_owns_cblob(true);

      SetBlobStrokeWidth(pix, newblob);

      port_box_it.add_after_then_move(newblob);

    }

    port_block_it.add_after_then_move(port_block);

  }

}

/**********************************************************************

 * find_components

 *

 * Find the C_OUTLINEs of the connected components in each block, put them

 * in C_BLOBs, and filter them by size, putting the different size

 * grades on different lists in the matching TO_BLOCK in to_blocks.

 **********************************************************************/

void Textord::find_components(Image pix, BLOCK_LIST *blocks, TO_BLOCK_LIST *to_blocks) {

  int width = pixGetWidth(pix);

  int height = pixGetHeight(pix);

  if (width > INT16_MAX || height > INT16_MAX) {

    tprintf("Input image too large! (%d, %d)\n", width, height);

    return; // Can't handle it.

  }

  BLOCK_IT block_it(blocks); // iterator

  for (block_it.mark_cycle_pt(); !block_it.cycled_list(); block_it.forward()) {

    BLOCK *block = block_it.data();

    if (block->pdblk.poly_block() == nullptr || block->pdblk.poly_block()->IsText()) {

      extract_edges(pix, block);

    }

  }

  assign_blobs_to_blocks2(pix, blocks, to_blocks);

  ICOORD page_tr(width, height);

  filter_blobs(page_tr, to_blocks, !textord_test_landscape);

}

/**********************************************************************

 * filter_blobs

 *

 * Sort the blobs into sizes in all the blocks for later work.

 **********************************************************************/

void Textord::filter_blobs(ICOORD page_tr,        // top right

                           TO_BLOCK_LIST *blocks, // output list

                           bool testing_on) {     // for plotting

  TO_BLOCK_IT block_it = blocks;                  // destination iterator

  TO_BLOCK *block;                                // created block

#ifndef GRAPHICS_DISABLED

  if (to_win != nullptr) {

    to_win->Clear();

  }

#endif // !GRAPHICS_DISABLED

  for (block_it.mark_cycle_pt(); !block_it.cycled_list(); block_it.forward()) {

    block = block_it.data();

    block->line_size = filter_noise_blobs(&block->blobs, &block->noise_blobs, &block->small_blobs,

                                          &block->large_blobs);

    if (block->line_size == 0) {

      block->line_size = 1;

    }

    block->line_spacing =

        block->line_size *

        (tesseract::CCStruct::kDescenderFraction + tesseract::CCStruct::kXHeightFraction +

         2 * tesseract::CCStruct::kAscenderFraction) /

        tesseract::CCStruct::kXHeightFraction;

    block->line_size *= textord_min_linesize;

    block->max_blob_size = block->line_size * textord_excess_blobsize;

#ifndef GRAPHICS_DISABLED

    if (textord_show_blobs && testing_on) {

      if (to_win == nullptr) {

        create_to_win(page_tr);

      }

      block->plot_graded_blobs(to_win);

    }

    if (textord_show_boxes && testing_on) {

      if (to_win == nullptr) {

        create_to_win(page_tr);

      }

      plot_box_list(to_win, &block->noise_blobs, ScrollView::WHITE);

      plot_box_list(to_win, &block->small_blobs, ScrollView::WHITE);

      plot_box_list(to_win, &block->large_blobs, ScrollView::WHITE);

      plot_box_list(to_win, &block->blobs, ScrollView::WHITE);

    }

#endif // !GRAPHICS_DISABLED

  }

}

/**********************************************************************

 * filter_noise_blobs

 *

 * Move small blobs to a separate list.

 **********************************************************************/

float Textord::filter_noise_blobs(BLOBNBOX_LIST *src_list,     // original list

                                  BLOBNBOX_LIST *noise_list,   // noise list

                                  BLOBNBOX_LIST *small_list,   // small blobs

                                  BLOBNBOX_LIST *large_list) { // large blobs

  int16_t height;                                              // height of blob

  int16_t width;                                               // of blob

  BLOBNBOX *blob;                                              // current blob

  float initial_x;                                             // first guess

  BLOBNBOX_IT src_it = src_list;                               // iterators

  BLOBNBOX_IT noise_it = noise_list;

  BLOBNBOX_IT small_it = small_list;

  BLOBNBOX_IT large_it = large_list;

  STATS size_stats(0, MAX_NEAREST_DIST - 1);

  // blob heights

  float min_y; // size limits

  float max_y;

  float max_x;

  float max_height; // of good blobs

  for (src_it.mark_cycle_pt(); !src_it.cycled_list(); src_it.forward()) {

    blob = src_it.data();

    if (blob->bounding_box().height() < textord_max_noise_size) {

      noise_it.add_after_then_move(src_it.extract());

    } else if (blob->enclosed_area() >= blob->bounding_box().height() *

                                            blob->bounding_box().width() *

                                            textord_noise_area_ratio) {

      small_it.add_after_then_move(src_it.extract());

    }

  }

  for (src_it.mark_cycle_pt(); !src_it.cycled_list(); src_it.forward()) {

    size_stats.add(src_it.data()->bounding_box().height(), 1);

  }

  initial_x = size_stats.ile(textord_initialx_ile);

  max_y = ceil(initial_x *

               (tesseract::CCStruct::kDescenderFraction + tesseract::CCStruct::kXHeightFraction +

                2 * tesseract::CCStruct::kAscenderFraction) /

               tesseract::CCStruct::kXHeightFraction);

  min_y = std::floor(initial_x / 2);

  max_x = ceil(initial_x * textord_width_limit);

  small_it.move_to_first();

  for (small_it.mark_cycle_pt(); !small_it.cycled_list(); small_it.forward()) {

    height = small_it.data()->bounding_box().height();

    if (height > max_y) {

      large_it.add_after_then_move(small_it.extract());

    } else if (height >= min_y) {

      src_it.add_after_then_move(small_it.extract());

    }

  }

  size_stats.clear();

  for (src_it.mark_cycle_pt(); !src_it.cycled_list(); src_it.forward()) {

    height = src_it.data()->bounding_box().height();

    width = src_it.data()->bounding_box().width();

    if (height < min_y) {

      small_it.add_after_then_move(src_it.extract());

    } else if (height > max_y || width > max_x) {

      large_it.add_after_then_move(src_it.extract());

    } else {

      size_stats.add(height, 1);

    }

  }

  max_height = size_stats.ile(textord_initialasc_ile);

  //      tprintf("max_y=%g, min_y=%g, initial_x=%g, max_height=%g,",

  //              max_y,min_y,initial_x,max_height);

  max_height *= tesseract::CCStruct::kXHeightCapRatio;

  if (max_height > initial_x) {

    initial_x = max_height;

  }

  //      tprintf(" ret=%g\n",initial_x);

  return initial_x;

}

// Fixes the block so it obeys all the rules:

// Must have at least one ROW.

// Must have at least one WERD.

// WERDs contain a fake blob.

void Textord::cleanup_nontext_block(BLOCK *block) {

  // Non-text blocks must contain at least one row.

  ROW_IT row_it(block->row_list());

  if (row_it.empty()) {

    const TBOX &box = block->pdblk.bounding_box();

    float height = box.height();

    int32_t xstarts[2] = {box.left(), box.right()};

    double coeffs[3] = {0.0, 0.0, static_cast<double>(box.bottom())};

    ROW *row = new ROW(1, xstarts, coeffs, height / 2.0f, height / 4.0f, height / 4.0f, 0, 1);

    row_it.add_after_then_move(row);

  }

  // Each row must contain at least one word.

  for (row_it.mark_cycle_pt(); !row_it.cycled_list(); row_it.forward()) {

    ROW *row = row_it.data();

    WERD_IT w_it(row->word_list());

    if (w_it.empty()) {

      // Make a fake blob to put in the word.

      TBOX box = block->row_list()->singleton() ? block->pdblk.bounding_box() : row->bounding_box();

      C_BLOB *blob = C_BLOB::FakeBlob(box);

      C_BLOB_LIST blobs;

      C_BLOB_IT blob_it(&blobs);

      blob_it.add_after_then_move(blob);

      WERD *word = new WERD(&blobs, 0, nullptr);

      w_it.add_after_then_move(word);

    }

    // Each word must contain a fake blob.

    for (w_it.mark_cycle_pt(); !w_it.cycled_list(); w_it.forward()) {

      WERD *word = w_it.data();

      // Just assert that this is true, as it would be useful to find

      // out why it isn't.

      ASSERT_HOST(!word->cblob_list()->empty());

    }

    row->recalc_bounding_box();

  }

}

/**********************************************************************

 * cleanup_blocks

 *

 * Delete empty blocks, rows from the page.

 **********************************************************************/

void Textord::cleanup_blocks(bool clean_noise, BLOCK_LIST *blocks) {

  BLOCK_IT block_it = blocks; // iterator

  ROW_IT row_it;              // row iterator

  int num_rows = 0;

  int num_rows_all = 0;

  int num_blocks = 0;

  int num_blocks_all = 0;

  for (block_it.mark_cycle_pt(); !block_it.cycled_list(); block_it.forward()) {

    BLOCK *block = block_it.data();

    if (block->pdblk.poly_block() != nullptr && !block->pdblk.poly_block()->IsText()) {

      cleanup_nontext_block(block);

      continue;

    }

    num_rows = 0;

    num_rows_all = 0;

    if (clean_noise) {

      row_it.set_to_list(block->row_list());

      for (row_it.mark_cycle_pt(); !row_it.cycled_list(); row_it.forward()) {

        ROW *row = row_it.data();

        ++num_rows_all;

        clean_small_noise_from_words(row);

        if ((textord_noise_rejrows && !row->word_list()->empty() && clean_noise_from_row(row)) ||

            row->word_list()->empty()) {

          delete row_it.extract(); // lose empty row.

        } else {

          if (textord_noise_rejwords) {

            clean_noise_from_words(row_it.data());

          }

          if (textord_blshift_maxshift >= 0) {

            tweak_row_baseline(row, textord_blshift_maxshift, textord_blshift_xfraction);

          }

          ++num_rows;

        }

      }

    }

    if (block->row_list()->empty()) {

      delete block_it.extract(); // Lose empty text blocks.

    } else {

      ++num_blocks;

    }

    ++num_blocks_all;

    if (textord_noise_debug) {

      tprintf("cleanup_blocks: # rows = %d / %d\n", num_rows, num_rows_all);

    }

  }

  if (textord_noise_debug) {

    tprintf("cleanup_blocks: # blocks = %d / %d\n", num_blocks, num_blocks_all);

  }

}

/**********************************************************************

 * clean_noise_from_row

 *

 * Move blobs of words from rows of garbage into the reject blobs list.

 **********************************************************************/

bool Textord::clean_noise_from_row( // remove empties

    ROW *row                        // row to clean

) {

  bool testing_on;

  TBOX blob_box;            // bounding box

  C_BLOB *blob;             // current blob

  C_OUTLINE *outline;       // current outline

  WERD *word;               // current word

  int32_t blob_size;        // biggest size

  int32_t trans_count = 0;  // no of transitions

  int32_t trans_threshold;  // noise tolerance

  int32_t dot_count;        // small objects

  int32_t norm_count;       // normal objects

  int32_t super_norm_count; // real char-like

                            // words of row

  WERD_IT word_it = row->word_list();

  C_BLOB_IT blob_it;   // blob iterator

  C_OUTLINE_IT out_it; // outline iterator

  testing_on = textord_test_y > row->base_line(textord_test_x) && textord_show_blobs &&

               textord_test_y < row->base_line(textord_test_x) + row->x_height();

  dot_count = 0;

  norm_count = 0;

  super_norm_count = 0;

  for (word_it.mark_cycle_pt(); !word_it.cycled_list(); word_it.forward()) {

    word = word_it.data(); // current word

                           // blobs in word

    blob_it.set_to_list(word->cblob_list());

    for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {

      blob = blob_it.data();

      if (!word->flag(W_DONT_CHOP)) {

        // get outlines

        out_it.set_to_list(blob->out_list());

        for (out_it.mark_cycle_pt(); !out_it.cycled_list(); out_it.forward()) {

          outline = out_it.data();

          blob_box = outline->bounding_box();

          blob_size = blob_box.width() > blob_box.height() ? blob_box.width() : blob_box.height();

          if (blob_size < textord_noise_sizelimit * row->x_height()) {

            dot_count++; // count small outlines

          }

          if (!outline->child()->empty() &&

              blob_box.height() < (1 + textord_noise_syfract) * row->x_height() &&

              blob_box.height() > (1 - textord_noise_syfract) * row->x_height() &&

              blob_box.width() < (1 + textord_noise_sxfract) * row->x_height() &&

              blob_box.width() > (1 - textord_noise_sxfract) * row->x_height()) {

            super_norm_count++; // count small outlines

          }

        }

      } else {

        super_norm_count++;

      }

      blob_box = blob->bounding_box();

      blob_size = blob_box.width() > blob_box.height() ? blob_box.width() : blob_box.height();

      if (blob_size >= textord_noise_sizelimit * row->x_height() &&

          blob_size < row->x_height() * 2) {

        trans_threshold = blob_size / textord_noise_sizefraction;

        trans_count = blob->count_transitions(trans_threshold);

        if (trans_count < textord_noise_translimit) {

          norm_count++;

        }

      } else if (blob_box.height() > row->x_height() * 2 &&

                 (!word_it.at_first() || !blob_it.at_first())) {

        dot_count += 2;

      }

      if (testing_on) {

        tprintf("Blob at (%d,%d) -> (%d,%d), ols=%d, tc=%d, bldiff=%g\n", blob_box.left(),

                blob_box.bottom(), blob_box.right(), blob_box.top(), blob->out_list()->length(),

                trans_count, blob_box.bottom() - row->base_line(blob_box.left()));

      }

    }

  }

  // TODO: check whether `&& super_norm_count < textord_noise_sncount`should always be added here.

  bool rejected = dot_count > norm_count * textord_noise_normratio &&

                  dot_count > 2;

  if (textord_noise_debug) {

    tprintf("Row ending at (%d,%g):", blob_box.right(), row->base_line(blob_box.right()));

    tprintf(" R=%g, dc=%d, nc=%d, %s\n",

            norm_count > 0 ? static_cast<float>(dot_count) / norm_count : 9999, dot_count,

            norm_count,

            rejected? "REJECTED": "ACCEPTED");

  }

  return super_norm_count < textord_noise_sncount && rejected;

}

/**********************************************************************

 * clean_noise_from_words

 *

 * Move blobs of words from rows of garbage into the reject blobs list.

 **********************************************************************/

void Textord::clean_noise_from_words( // remove empties

    ROW *row                          // row to clean

) {

  TBOX blob_box;           // bounding box

  C_BLOB *blob;            // current blob

  C_OUTLINE *outline;      // current outline

  WERD *word;              // current word

  int32_t blob_size;       // biggest size

  int32_t trans_count;     // no of transitions

  int32_t trans_threshold; // noise tolerance

  int32_t dot_count;       // small objects

  int32_t norm_count;      // normal objects

  int32_t dud_words;       // number discarded

  int32_t ok_words;        // number remaining

  int32_t word_index;      // current word

                           // words of row

  WERD_IT word_it = row->word_list();

  C_BLOB_IT blob_it;   // blob iterator

  C_OUTLINE_IT out_it; // outline iterator

  ok_words = word_it.length();

  if (ok_words == 0 || textord_no_rejects) {

    return;

  }

  // was it chucked

  std::vector<int8_t> word_dud(ok_words);

  dud_words = 0;

  ok_words = 0;

  word_index = 0;

  for (word_it.mark_cycle_pt(); !word_it.cycled_list(); word_it.forward()) {

    word = word_it.data(); // current word

    dot_count = 0;

    norm_count = 0;

    // blobs in word

    blob_it.set_to_list(word->cblob_list());

    for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {

      blob = blob_it.data();

      if (!word->flag(W_DONT_CHOP)) {

        // get outlines

        out_it.set_to_list(blob->out_list());

        for (out_it.mark_cycle_pt(); !out_it.cycled_list(); out_it.forward()) {

          outline = out_it.data();

          blob_box = outline->bounding_box();

          blob_size = blob_box.width() > blob_box.height() ? blob_box.width() : blob_box.height();

          if (blob_size < textord_noise_sizelimit * row->x_height()) {

            dot_count++; // count small outlines

          }

          if (!outline->child()->empty() &&

              blob_box.height() < (1 + textord_noise_syfract) * row->x_height() &&

              blob_box.height() > (1 - textord_noise_syfract) * row->x_height() &&

              blob_box.width() < (1 + textord_noise_sxfract) * row->x_height() &&

              blob_box.width() > (1 - textord_noise_sxfract) * row->x_height()) {

            norm_count++; // count small outlines

          }

        }

      } else {

        norm_count++;

      }

      blob_box = blob->bounding_box();

      blob_size = blob_box.width() > blob_box.height() ? blob_box.width() : blob_box.height();

      if (blob_size >= textord_noise_sizelimit * row->x_height() &&

          blob_size < row->x_height() * 2) {

        trans_threshold = blob_size / textord_noise_sizefraction;

        trans_count = blob->count_transitions(trans_threshold);

        if (trans_count < textord_noise_translimit) {

          norm_count++;

        }

      } else if (blob_box.height() > row->x_height() * 2 &&

                 (!word_it.at_first() || !blob_it.at_first())) {

        dot_count += 2;

      }

    }

    if (dot_count > 2 && !word->flag(W_REP_CHAR)) {

      if (dot_count > norm_count * textord_noise_normratio * 2) {

        word_dud[word_index] = 2;

      } else if (dot_count > norm_count * textord_noise_normratio) {

        word_dud[word_index] = 1;

      } else {

        word_dud[word_index] = 0;

      }

    } else {

      word_dud[word_index] = 0;

    }

    if (word_dud[word_index] == 2) {

      dud_words++;

    } else {

      ok_words++;

    }

    word_index++;

  }

  word_index = 0;

  for (word_it.mark_cycle_pt(); !word_it.cycled_list(); word_it.forward()) {

    if (word_dud[word_index] == 2 || (word_dud[word_index] == 1 && dud_words > ok_words)) {

      word = word_it.data(); // Current word.

      // Previously we threw away the entire word.

      // Now just aggressively throw all small blobs into the reject list, where

      // the classifier can decide whether they are actually needed.

      word->CleanNoise(textord_noise_sizelimit * row->x_height());

    }

    word_index++;

  }

}

// Remove outlines that are a tiny fraction in either width or height

// of the word height.

void Textord::clean_small_noise_from_words(ROW *row) {

  WERD_IT word_it(row->word_list());

  for (word_it.mark_cycle_pt(); !word_it.cycled_list(); word_it.forward()) {

    WERD *word = word_it.data();

    int min_size = static_cast<int>(textord_noise_hfract * word->bounding_box().height() + 0.5);

    C_BLOB_IT blob_it(word->cblob_list());

    for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {

      C_BLOB *blob = blob_it.data();

      C_OUTLINE_IT out_it(blob->out_list());

      for (out_it.mark_cycle_pt(); !out_it.cycled_list(); out_it.forward()) {

        C_OUTLINE *outline = out_it.data();

        outline->RemoveSmallRecursive(min_size, &out_it);

      }

      if (blob->out_list()->empty()) {

        delete blob_it.extract();

      }

    }

    if (word->cblob_list()->empty()) {

      if (!word_it.at_last()) {

        // The next word is no longer a fuzzy non space if it was before,

        // since the word before is about to be deleted.

        WERD *next_word = word_it.data_relative(1);

        if (next_word->flag(W_FUZZY_NON)) {

          next_word->set_flag(W_FUZZY_NON, false);

        }

      }

      delete word_it.extract();

    }

  }

}

// Local struct to hold a group of blocks.

struct BlockGroup {

  BlockGroup() : rotation(1.0f, 0.0f), angle(0.0f), min_xheight(1.0f) {}

  explicit BlockGroup(BLOCK *block)

      : bounding_box(block->pdblk.bounding_box())

      , rotation(block->re_rotation())

      , angle(block->re_rotation().angle())

      , min_xheight(block->x_height()) {

    blocks.push_back(block);

  }

  // Union of block bounding boxes.

  TBOX bounding_box;

  // Common rotation of the blocks.

  FCOORD rotation;

  // Angle of rotation.

  float angle;

  // Min xheight of the blocks.

  float min_xheight;

  // Collection of borrowed pointers to the blocks in the group.

  std::vector<BLOCK *> blocks;

};

// Groups blocks by rotation, then, for each group, makes a WordGrid and calls

// TransferDiacriticsToWords to copy the diacritic blobs to the most

// appropriate words in the group of blocks. Source blobs are not touched.

void Textord::TransferDiacriticsToBlockGroups(BLOBNBOX_LIST *diacritic_blobs, BLOCK_LIST *blocks) {

  // Angle difference larger than this is too much to consider equal.

  // They should only be in multiples of M_PI/2 anyway.

  const double kMaxAngleDiff = 0.01; // About 0.6 degrees.

  std::vector<std::unique_ptr<BlockGroup>> groups;

  BLOCK_IT bk_it(blocks);

  for (bk_it.mark_cycle_pt(); !bk_it.cycled_list(); bk_it.forward()) {

    BLOCK *block = bk_it.data();

    if (block->pdblk.poly_block() != nullptr && !block->pdblk.poly_block()->IsText()) {

      continue;

    }

    // Linear search of the groups to find a matching rotation.

    float block_angle = block->re_rotation().angle();

    int best_g = 0;

    float best_angle_diff = FLT_MAX;

    for (const auto &group : groups) {

      double angle_diff = std::fabs(block_angle - group->angle);

      if (angle_diff > M_PI) {

        angle_diff = fabs(angle_diff - 2.0 * M_PI);

      }

      if (angle_diff < best_angle_diff) {

        best_angle_diff = angle_diff;

        best_g = &group - &groups[0];

      }

    }

    if (best_angle_diff > kMaxAngleDiff) {

      groups.push_back(std::make_unique<BlockGroup>(block));

    } else {

      groups[best_g]->blocks.push_back(block);

      groups[best_g]->bounding_box += block->pdblk.bounding_box();

      float x_height = block->x_height();

      if (x_height < groups[best_g]->min_xheight) {

        groups[best_g]->min_xheight = x_height;

      }

    }

  }

  // Now process each group of blocks.

  std::vector<std::unique_ptr<WordWithBox>> word_ptrs;

  for (const auto &group : groups) {

    if (group->bounding_box.null_box()) {

      continue;

    }

    WordGrid word_grid(group->min_xheight, group->bounding_box.botleft(),

                       group->bounding_box.topright());

    for (auto b : group->blocks) {

      ROW_IT row_it(b->row_list());

      for (row_it.mark_cycle_pt(); !row_it.cycled_list(); row_it.forward()) {

        ROW *row = row_it.data();

        // Put the words of the row into the grid.

        WERD_IT w_it(row->word_list());

        for (w_it.mark_cycle_pt(); !w_it.cycled_list(); w_it.forward()) {

          WERD *word = w_it.data();

          auto box_word = std::make_unique<WordWithBox>(word);

          word_grid.InsertBBox(true, true, box_word.get());

          // Save the pointer where it will be auto-deleted.

          word_ptrs.emplace_back(std::move(box_word));

        }

      }

    }

    FCOORD rotation = group->rotation;

    // Make it a forward rotation that will transform blob coords to block.

    rotation.set_y(-rotation.y());

    TransferDiacriticsToWords(diacritic_blobs, rotation, &word_grid);

  }

}

// Places a copy of blobs that are near a word (after applying rotation to the

// blob) in the most appropriate word, unless there is doubt, in which case a

// blob can end up in two words. Source blobs are not touched.

void Textord::TransferDiacriticsToWords(BLOBNBOX_LIST *diacritic_blobs, const FCOORD &rotation,

                                        WordGrid *word_grid) {

  WordSearch ws(word_grid);

  BLOBNBOX_IT b_it(diacritic_blobs);

  // Apply rotation to each blob before finding the nearest words. The rotation

  // allows us to only consider above/below placement and not left/right on

  // vertical text, because all text is horizontal here.

  for (b_it.mark_cycle_pt(); !b_it.cycled_list(); b_it.forward()) {

    BLOBNBOX *blobnbox = b_it.data();

    TBOX blob_box = blobnbox->bounding_box();

    blob_box.rotate(rotation);

    ws.StartRectSearch(blob_box);

    // Above/below refer to word position relative to diacritic. Since some

    // scripts eg Kannada/Telugu habitually put diacritics below words, and

    // others eg Thai/Vietnamese/Latin put most diacritics above words, try

    // for both if there isn't much in it.

    WordWithBox *best_above_word = nullptr;

    WordWithBox *best_below_word = nullptr;

    int best_above_distance = 0;

    int best_below_distance = 0;

    for (WordWithBox *word = ws.NextRectSearch(); word != nullptr; word = ws.NextRectSearch()) {

      if (word->word()->flag(W_REP_CHAR)) {

        continue;

      }

      TBOX word_box = word->true_bounding_box();

      int x_distance = blob_box.x_gap(word_box);

      int y_distance = blob_box.y_gap(word_box);

      if (x_distance > 0) {

        // Arbitrarily divide x-distance by 2 if there is a major y overlap,

        // and the word is to the left of the diacritic. If the

        // diacritic is a dropped broken character between two words, this will

        // help send all the pieces to a single word, instead of splitting them

        // over the 2 words.

        if (word_box.major_y_overlap(blob_box) && blob_box.left() > word_box.right()) {

          x_distance /= 2;

        }

        y_distance += x_distance;

      }

      if (word_box.y_middle() > blob_box.y_middle() &&

          (best_above_word == nullptr || y_distance < best_above_distance)) {

        best_above_word = word;

        best_above_distance = y_distance;

      }

      if (word_box.y_middle() <= blob_box.y_middle() &&

          (best_below_word == nullptr || y_distance < best_below_distance)) {

        best_below_word = word;

        best_below_distance = y_distance;

      }

    }

    bool above_good = best_above_word != nullptr &&

                      (best_below_word == nullptr ||

                       best_above_distance < best_below_distance + blob_box.height());

    bool below_good = best_below_word != nullptr && best_below_word != best_above_word &&

                      (best_above_word == nullptr ||

                       best_below_distance < best_above_distance + blob_box.height());

    if (below_good) {

      C_BLOB *copied_blob = C_BLOB::deep_copy(blobnbox->cblob());

      copied_blob->rotate(rotation);

      // Put the blob into the word's reject blobs list.

      C_BLOB_IT blob_it(best_below_word->RejBlobs());

      blob_it.add_to_end(copied_blob);

    }

    if (above_good) {

      C_BLOB *copied_blob = C_BLOB::deep_copy(blobnbox->cblob());

      copied_blob->rotate(rotation);

      // Put the blob into the word's reject blobs list.

      C_BLOB_IT blob_it(best_above_word->RejBlobs());

      blob_it.add_to_end(copied_blob);

    }

  }

}

/**********************************************************************

 * tweak_row_baseline

 *

 * Shift baseline to fit the blobs more accurately where they are

 * close enough.

 **********************************************************************/

void tweak_row_baseline(ROW *row, double blshift_maxshift, double blshift_xfraction) {

  TBOX blob_box;      // bounding box

  C_BLOB *blob;       // current blob

  WERD *word;         // current word

  int32_t blob_count; // no of blobs

  int32_t src_index;  // source segment

  int32_t dest_index; // destination segment

  float ydiff;        // baseline error

  float x_centre;     // centre of blob

                      // words of row

  WERD_IT word_it = row->word_list();

  C_BLOB_IT blob_it; // blob iterator

  blob_count = 0;

  for (word_it.mark_cycle_pt(); !word_it.cycled_list(); word_it.forward()) {

    word = word_it.data(); // current word

                           // get total blobs

    blob_count += word->cblob_list()->length();

  }

  if (blob_count == 0) {

    return;

  }

  // spline segments

  std::vector<int32_t> xstarts(blob_count + row->baseline.segments + 1);

  // spline coeffs

  std::vector<double> coeffs((blob_count + row->baseline.segments) * 3);

  src_index = 0;

  dest_index = 0;

  xstarts[0] = row->baseline.xcoords[0];

  for (word_it.mark_cycle_pt(); !word_it.cycled_list(); word_it.forward()) {

    word = word_it.data(); // current word

                           // blobs in word

    blob_it.set_to_list(word->cblob_list());

    for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {

      blob = blob_it.data();

      blob_box = blob->bounding_box();

      x_centre = (blob_box.left() + blob_box.right()) / 2.0;

      ydiff = blob_box.bottom() - row->base_line(x_centre);

      if (ydiff < 0) {

        ydiff = -ydiff / row->x_height();

      } else {

        ydiff = ydiff / row->x_height();

      }

      if (ydiff < blshift_maxshift && blob_box.height() / row->x_height() > blshift_xfraction) {

        if (xstarts[dest_index] >= x_centre) {

          xstarts[dest_index] = blob_box.left();

        }

        coeffs[dest_index * 3] = 0;

        coeffs[dest_index * 3 + 1] = 0;

        coeffs[dest_index * 3 + 2] = blob_box.bottom();

        // shift it

        dest_index++;

        xstarts[dest_index] = blob_box.right() + 1;

      } else {

        if (xstarts[dest_index] <= x_centre) {

          while (row->baseline.xcoords[src_index + 1] <= x_centre &&

                 src_index < row->baseline.segments - 1) {

            if (row->baseline.xcoords[src_index + 1] > xstarts[dest_index]) {

              coeffs[dest_index * 3] = row->baseline.quadratics[src_index].a;

              coeffs[dest_index * 3 + 1] = row->baseline.quadratics[src_index].b;

              coeffs[dest_index * 3 + 2] = row->baseline.quadratics[src_index].c;

              dest_index++;

              xstarts[dest_index] = row->baseline.xcoords[src_index + 1];

            }

            src_index++;

          }

          coeffs[dest_index * 3] = row->baseline.quadratics[src_index].a;

          coeffs[dest_index * 3 + 1] = row->baseline.quadratics[src_index].b;

          coeffs[dest_index * 3 + 2] = row->baseline.quadratics[src_index].c;

          dest_index++;

          xstarts[dest_index] = row->baseline.xcoords[src_index + 1];

        }

      }

    }

  }

  while (src_index < row->baseline.segments &&

         row->baseline.xcoords[src_index + 1] <= xstarts[dest_index]) {

    src_index++;

  }

  while (src_index < row->baseline.segments) {

    coeffs[dest_index * 3] = row->baseline.quadratics[src_index].a;

    coeffs[dest_index * 3 + 1] = row->baseline.quadratics[src_index].b;

    coeffs[dest_index * 3 + 2] = row->baseline.quadratics[src_index].c;

    dest_index++;

    src_index++;

    xstarts[dest_index] = row->baseline.xcoords[src_index];

  }

  // turn to spline

  row->baseline = QSPLINE(dest_index, &xstarts[0], &coeffs[0]);

}

} // namespace tesseract