Ejemplo n.º 1
0
// Build a ragged TabVector by copying another's direction, shifting it
// to match the given blob, and making its initial extent the height
// of the blob, but its extended bounds from the bounds of the original.
TabVector::TabVector(const TabVector& src, TabAlignment alignment,
                     const ICOORD& vertical_skew, BLOBNBOX* blob)
  : 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:");
}
Ejemplo n.º 2
0
/**
 * Sets up auto page segmentation, determines the orientation, and corrects it.
 * Somewhat arbitrary chunk of functionality, factored out of AutoPageSeg to
 * facilitate testing.
 * photo_mask_pix is a pointer to a NULL pointer that will be filled on return
 * with the leptonica photo mask, which must be pixDestroyed by the caller.
 * to_blocks is an empty list that will be filled with (usually a single)
 * block that is used during layout analysis. This ugly API is required
 * because of the possibility of a unlv zone file.
 * TODO(rays) clean this up.
 * See AutoPageSeg for other arguments.
 * The returned ColumnFinder must be deleted after use.
 */
ColumnFinder* Tesseract::SetupPageSegAndDetectOrientation(
    bool single_column, bool osd, bool only_osd,
    BLOCK_LIST* blocks, Tesseract* osd_tess, OSResults* osr,
    TO_BLOCK_LIST* to_blocks, Pix** photo_mask_pix, Pix** music_mask_pix) {
  int vertical_x = 0;
  int vertical_y = 1;
  TabVector_LIST v_lines;
  TabVector_LIST h_lines;
  ICOORD bleft(0, 0);

  ASSERT_HOST(pix_binary_ != NULL);
  if (tessedit_dump_pageseg_images) {
    pixWrite("tessinput.png", pix_binary_, IFF_PNG);
  }
  // Leptonica is used to find the rule/separator lines in the input.
  LineFinder::FindAndRemoveLines(source_resolution_,
                                 textord_tabfind_show_vlines, pix_binary_,
                                 &vertical_x, &vertical_y, music_mask_pix,
                                 &v_lines, &h_lines);
  if (tessedit_dump_pageseg_images)
    pixWrite("tessnolines.png", pix_binary_, IFF_PNG);
  // Leptonica is used to find a mask of the photo regions in the input.
  *photo_mask_pix = ImageFind::FindImages(pix_binary_);
  if (tessedit_dump_pageseg_images)
    pixWrite("tessnoimages.png", pix_binary_, IFF_PNG);
  if (single_column)
    v_lines.clear();

  // The rest of the algorithm uses the usual connected components.
  textord_.find_components(pix_binary_, blocks, to_blocks);

  TO_BLOCK_IT to_block_it(to_blocks);
  // There must be exactly one input block.
  // TODO(rays) handle new textline finding with a UNLV zone file.
  ASSERT_HOST(to_blocks->singleton());
  TO_BLOCK* to_block = to_block_it.data();
  TBOX blkbox = to_block->block->bounding_box();
  ColumnFinder* finder = NULL;

  if (to_block->line_size >= 2) {
    finder = new ColumnFinder(static_cast<int>(to_block->line_size),
                              blkbox.botleft(), blkbox.topright(),
                              source_resolution_,
                              &v_lines, &h_lines, vertical_x, vertical_y);

    finder->SetupAndFilterNoise(*photo_mask_pix, to_block);

    if (equ_detect_) {
      equ_detect_->LabelSpecialText(to_block);
    }

    BLOBNBOX_CLIST osd_blobs;
    // osd_orientation is the number of 90 degree rotations to make the
    // characters upright. (See osdetect.h for precise definition.)
    // We want the text lines horizontal, (vertical text indicates vertical
    // textlines) which may conflict (eg vertically written CJK).
    int osd_orientation = 0;
    bool vertical_text = finder->IsVerticallyAlignedText(to_block, &osd_blobs);
    if (osd && osd_tess != NULL && osr != NULL) {
      os_detect_blobs(&osd_blobs, osr, osd_tess);
      if (only_osd) {
        delete finder;
        return NULL;
      }
      osd_orientation = osr->best_result.orientation_id;
      double osd_score = osr->orientations[osd_orientation];
      double osd_margin = min_orientation_margin * 2;
      for (int i = 0; i < 4; ++i) {
        if (i != osd_orientation &&
            osd_score - osr->orientations[i] < osd_margin) {
          osd_margin = osd_score - osr->orientations[i];
        }
      }
      if (osd_margin < min_orientation_margin) {
        // The margin is weak.
        int best_script_id = osr->best_result.script_id;
        bool cjk = (best_script_id == osd_tess->unicharset.han_sid()) ||
            (best_script_id == osd_tess->unicharset.hiragana_sid()) ||
            (best_script_id == osd_tess->unicharset.katakana_sid());

        if (!cjk && !vertical_text && osd_orientation == 2) {
          // upside down latin text is improbable with such a weak margin.
          tprintf("OSD: Weak margin (%.2f), horiz textlines, not CJK: "
                  "Don't rotate.\n", osd_margin);
          osd_orientation = 0;
        } else {
          tprintf("OSD: Weak margin (%.2f) for %d blob text block, "
                  "but using orientation anyway: %d\n",
                  osd_blobs.length(), osd_margin, osd_orientation);
        }
      }
    }
    osd_blobs.shallow_clear();
    finder->CorrectOrientation(to_block, vertical_text, osd_orientation);
  }

  return finder;
}
Ejemplo n.º 3
0
/**
 * Sets up auto page segmentation, determines the orientation, and corrects it.
 * Somewhat arbitrary chunk of functionality, factored out of AutoPageSeg to
 * facilitate testing.
 * photo_mask_pix is a pointer to a NULL pointer that will be filled on return
 * with the leptonica photo mask, which must be pixDestroyed by the caller.
 * to_blocks is an empty list that will be filled with (usually a single)
 * block that is used during layout analysis. This ugly API is required
 * because of the possibility of a unlv zone file.
 * TODO(rays) clean this up.
 * See AutoPageSeg for other arguments.
 * The returned ColumnFinder must be deleted after use.
 */
ColumnFinder* Tesseract::SetupPageSegAndDetectOrientation(
    PageSegMode pageseg_mode, BLOCK_LIST* blocks, Tesseract* osd_tess,
    OSResults* osr, TO_BLOCK_LIST* to_blocks, Pix** photo_mask_pix,
    Pix** music_mask_pix) {
  int vertical_x = 0;
  int vertical_y = 1;
  TabVector_LIST v_lines;
  TabVector_LIST h_lines;
  ICOORD bleft(0, 0);

  ASSERT_HOST(pix_binary_ != NULL);
  if (tessedit_dump_pageseg_images) {
    pixa_debug_.AddPix(pix_binary_, "PageSegInput");
  }
  // Leptonica is used to find the rule/separator lines in the input.
  LineFinder::FindAndRemoveLines(source_resolution_,
                                 textord_tabfind_show_vlines, pix_binary_,
                                 &vertical_x, &vertical_y, music_mask_pix,
                                 &v_lines, &h_lines);
  if (tessedit_dump_pageseg_images) {
    pixa_debug_.AddPix(pix_binary_, "NoLines");
  }
  // Leptonica is used to find a mask of the photo regions in the input.
  *photo_mask_pix = ImageFind::FindImages(pix_binary_, &pixa_debug_);
  if (tessedit_dump_pageseg_images) {
    pixa_debug_.AddPix(pix_binary_, "NoImages");
  }
  if (!PSM_COL_FIND_ENABLED(pageseg_mode)) v_lines.clear();

  // The rest of the algorithm uses the usual connected components.
  textord_.find_components(pix_binary_, blocks, to_blocks);

  TO_BLOCK_IT to_block_it(to_blocks);
  // There must be exactly one input block.
  // TODO(rays) handle new textline finding with a UNLV zone file.
  ASSERT_HOST(to_blocks->singleton());
  TO_BLOCK* to_block = to_block_it.data();
  TBOX blkbox = to_block->block->bounding_box();
  ColumnFinder* finder = NULL;
  int estimated_resolution = source_resolution_;
  if (source_resolution_ == kMinCredibleResolution) {
    // Try to estimate resolution from typical body text size.
    int res = IntCastRounded(to_block->line_size * kResolutionEstimationFactor);
    if (res > estimated_resolution && res < kMaxCredibleResolution) {
      estimated_resolution = res;
      tprintf("Estimating resolution as %d\n", estimated_resolution);
    }
  }

  if (to_block->line_size >= 2) {
    finder = new ColumnFinder(static_cast<int>(to_block->line_size),
                              blkbox.botleft(), blkbox.topright(),
                              estimated_resolution, textord_use_cjk_fp_model,
                              textord_tabfind_aligned_gap_fraction, &v_lines,
                              &h_lines, vertical_x, vertical_y);

    finder->SetupAndFilterNoise(pageseg_mode, *photo_mask_pix, to_block);

    if (equ_detect_) {
      equ_detect_->LabelSpecialText(to_block);
    }

    BLOBNBOX_CLIST osd_blobs;
    // osd_orientation is the number of 90 degree rotations to make the
    // characters upright. (See osdetect.h for precise definition.)
    // We want the text lines horizontal, (vertical text indicates vertical
    // textlines) which may conflict (eg vertically written CJK).
    int osd_orientation = 0;
    bool vertical_text = textord_tabfind_force_vertical_text ||
                         pageseg_mode == PSM_SINGLE_BLOCK_VERT_TEXT;
    if (!vertical_text && textord_tabfind_vertical_text &&
        PSM_ORIENTATION_ENABLED(pageseg_mode)) {
      vertical_text =
          finder->IsVerticallyAlignedText(textord_tabfind_vertical_text_ratio,
                                          to_block, &osd_blobs);
    }
    if (PSM_OSD_ENABLED(pageseg_mode) && osd_tess != NULL && osr != NULL) {
      GenericVector<int> osd_scripts;
      if (osd_tess != this) {
        // We are running osd as part of layout analysis, so constrain the
        // scripts to those allowed by *this.
        AddAllScriptsConverted(unicharset, osd_tess->unicharset, &osd_scripts);
        for (int s = 0; s < sub_langs_.size(); ++s) {
          AddAllScriptsConverted(sub_langs_[s]->unicharset,
                                 osd_tess->unicharset, &osd_scripts);
        }
      }
      os_detect_blobs(&osd_scripts, &osd_blobs, osr, osd_tess);
      if (pageseg_mode == PSM_OSD_ONLY) {
        delete finder;
        return NULL;
      }
      osd_orientation = osr->best_result.orientation_id;
      double osd_score = osr->orientations[osd_orientation];
      double osd_margin = min_orientation_margin * 2;
      for (int i = 0; i < 4; ++i) {
        if (i != osd_orientation &&
            osd_score - osr->orientations[i] < osd_margin) {
          osd_margin = osd_score - osr->orientations[i];
        }
      }
      int best_script_id = osr->best_result.script_id;
      const char* best_script_str =
          osd_tess->unicharset.get_script_from_script_id(best_script_id);
      bool cjk = best_script_id == osd_tess->unicharset.han_sid() ||
          best_script_id == osd_tess->unicharset.hiragana_sid() ||
          best_script_id == osd_tess->unicharset.katakana_sid() ||
          strcmp("Japanese", best_script_str) == 0 ||
          strcmp("Korean", best_script_str) == 0 ||
          strcmp("Hangul", best_script_str) == 0;
      if (cjk) {
        finder->set_cjk_script(true);
      }
      if (osd_margin < min_orientation_margin) {
        // The margin is weak.
        if (!cjk && !vertical_text && osd_orientation == 2) {
          // upside down latin text is improbable with such a weak margin.
          tprintf("OSD: Weak margin (%.2f), horiz textlines, not CJK: "
                  "Don't rotate.\n", osd_margin);
          osd_orientation = 0;
        } else {
          tprintf(
              "OSD: Weak margin (%.2f) for %d blob text block, "
              "but using orientation anyway: %d\n",
              osd_margin, osd_blobs.length(), osd_orientation);
        }
      }
    }
    osd_blobs.shallow_clear();
    finder->CorrectOrientation(to_block, vertical_text, osd_orientation);
  }

  return finder;
}
Ejemplo n.º 4
0
// Auto page segmentation. Divide the page image into blocks of uniform
// text linespacing and images.
// Width, height and resolution are derived from the input image.
// If the pix is non-NULL, then it is assumed to be the input, and it is
// copied to the image, otherwise the image is used directly.
// The output goes in the blocks list with corresponding TO_BLOCKs in the
// to_blocks list.
// If single_column is true, then no attempt is made to divide the image
// into columns, but multiple blocks are still made if the text is of
// non-uniform linespacing.
int Tesseract::AutoPageSeg(int width, int height, int resolution,
                           bool single_column, IMAGE* image,
                           BLOCK_LIST* blocks, TO_BLOCK_LIST* to_blocks) {
  int vertical_x = 0;
  int vertical_y = 1;
  TabVector_LIST v_lines;
  TabVector_LIST h_lines;
  ICOORD bleft(0, 0);
  Boxa* boxa = NULL;
  Pixa* pixa = NULL;
  // The blocks made by the ColumnFinder. Moved to blocks before return.
  BLOCK_LIST found_blocks;

#ifdef HAVE_LIBLEPT
  if (pix_binary_ != NULL) {
    if (textord_debug_images) {
      Pix* grey_pix = pixCreate(width, height, 8);
      // Printable images are light grey on white, but for screen display
      // they are black on dark grey so the other colors show up well.
      if (textord_debug_printable) {
        pixSetAll(grey_pix);
        pixSetMasked(grey_pix, pix_binary_, 192);
      } else {
        pixSetAllArbitrary(grey_pix, 64);
        pixSetMasked(grey_pix, pix_binary_, 0);
      }
      AlignedBlob::IncrementDebugPix();
      pixWrite(AlignedBlob::textord_debug_pix().string(), grey_pix, IFF_PNG);
      pixDestroy(&grey_pix);
    }
    if (tessedit_dump_pageseg_images)
      pixWrite("tessinput.png", pix_binary_, IFF_PNG);
    // Leptonica is used to find the lines and image regions in the input.
    LineFinder::FindVerticalLines(resolution, pix_binary_,
                                  &vertical_x, &vertical_y, &v_lines);
    LineFinder::FindHorizontalLines(resolution, pix_binary_, &h_lines);
    if (tessedit_dump_pageseg_images)
      pixWrite("tessnolines.png", pix_binary_, IFF_PNG);
    ImageFinder::FindImages(pix_binary_, &boxa, &pixa);
    if (tessedit_dump_pageseg_images)
      pixWrite("tessnoimages.png", pix_binary_, IFF_PNG);
    // Copy the Pix to the IMAGE.
    image->FromPix(pix_binary_);
    if (single_column)
      v_lines.clear();
  }
#endif
  TO_BLOCK_LIST land_blocks, port_blocks;
  TBOX page_box;
  // The rest of the algorithm uses the usual connected components.
  find_components(blocks, &land_blocks, &port_blocks, &page_box);

  TO_BLOCK_IT to_block_it(&port_blocks);
  ASSERT_HOST(!to_block_it.empty());
  for (to_block_it.mark_cycle_pt(); !to_block_it.cycled_list();
       to_block_it.forward()) {
    TO_BLOCK* to_block = to_block_it.data();
    TBOX blkbox = to_block->block->bounding_box();
    if (to_block->line_size >= 2) {
      // Note: if there are multiple blocks, then v_lines, boxa, and pixa
      // are empty on the next iteration, but in this case, we assume
      // that there aren't any interesting line separators or images, since
      // it means that we have a pre-defined unlv zone file.
      ColumnFinder finder(static_cast<int>(to_block->line_size),
                          blkbox.botleft(), blkbox.topright(),
                          &v_lines, &h_lines, vertical_x, vertical_y);
      if (finder.FindBlocks(height, resolution, single_column,
                            to_block, boxa, pixa, &found_blocks, to_blocks) < 0)
        return -1;
      finder.ComputeDeskewVectors(&deskew_, &reskew_);
      boxa = NULL;
      pixa = NULL;
    }
  }
#ifdef HAVE_LIBLEPT
  boxaDestroy(&boxa);
  pixaDestroy(&pixa);
#endif
  blocks->clear();
  BLOCK_IT block_it(blocks);
  // Move the found blocks to the input/output blocks.
  block_it.add_list_after(&found_blocks);

  if (textord_debug_images) {
    // The debug image is no longer needed so delete it.
    unlink(AlignedBlob::textord_debug_pix().string());
  }
  return 0;
}