#include <associate.h>

Static Public Member Functions
static void	ComputeStats (int col, int row, const AssociateStats parent_stats, int parent_path_length, bool fixed_pitch, float max_char_wh_ratio, const DENORM denorm, CHUNKS_RECORD chunks_record, int debug_level, AssociateStats stats)

static int	GetChunksWidth (WIDTH_RECORD *width_record, int start_blob, int last_blob)

static int	GetChunksGap (WIDTH_RECORD *width_record, int last_chunk)

static float	FixedPitchWidthCost (float norm_width, float right_gap, bool end_pos, float max_char_wh_ratio)

static float	FixedPitchGapCost (float norm_gap, bool end_pos)

Static Public Attributes
static const float	kMaxFixedPitchCharAspectRatio = 2.0f

static const float	kMinGap = 0.03f

Detailed Description

Definition at line 96 of file associate.h.

Member Function Documentation

void tesseract::AssociateUtils::ComputeStats	(	int	col,
		int	row,
		const AssociateStats *	parent_stats,
		int	parent_path_length,
		bool	fixed_pitch,
		float	max_char_wh_ratio,
		const DENORM *	denorm,
		CHUNKS_RECORD *	chunks_record,
		int	debug_level,
		AssociateStats *	stats
	)

static

Definition at line 37 of file associate.cpp.

                                                          {
   stats->Clear();
 
   if (debug_level > 0) {
     tprintf("AssociateUtils::ComputeStats() for col=%d, row=%d%s\n",
             col, row, fixed_pitch ? " (fixed pitch)" : "");
   }
   float normalizing_height = BASELINE_SCALE;
   // TODO(rays/daria) Can unicharset.script_has_xheight be useful here?
   if (fixed_pitch && denorm != NULL && denorm->row() != NULL) {
     // For fixed pitch language like CJK, we use the full text height
     // as the normalizing factor so we are not dependent on xheight
     // calculation.
     if (denorm->row()->body_size() > 0.0f) {
       normalizing_height = denorm->y_scale() * denorm->row()->body_size();
     } else {
       normalizing_height = denorm->y_scale() *
           (denorm->row()->x_height() + denorm->row()->ascenders());
     }
     if (debug_level > 0) {
       tprintf("normalizing height = %g (scale %g xheight %g ascenders %g)\n",
               normalizing_height, denorm->y_scale(), denorm->row()->x_height(),
               denorm->row()->ascenders());
     }
   }
   float wh_ratio =
     GetChunksWidth(chunks_record->chunk_widths, col, row) / normalizing_height;
   if (debug_level) tprintf("wh_ratio %g\n", wh_ratio);
   if (wh_ratio > max_char_wh_ratio) stats->bad_shape = true;
   if (fixed_pitch) {
     bool end_row = (row == (chunks_record->ratings->dimension() - 1));
 
     // Ensure that the blob has gaps on the left and the right sides
     // (except for beginning and ending punctuation) and that there is
     // no cutting through ink at the blob boundaries.
     if (col > 0) {
       float left_gap =
         GetChunksGap(chunks_record->chunk_widths, col-1) / normalizing_height;
       SEAM *left_seam =
         static_cast<SEAM *>(array_value(chunks_record->splits, col-1));
       if (debug_level) {
         tprintf("left_gap %g, left_seam %g\n", left_gap, left_seam->priority);
       }
       if ((!end_row && left_gap < kMinGap) || left_seam->priority > 0.0f) {
         stats->bad_shape = true;
       }
     }
     float right_gap = 0.0f;
     if (!end_row) {
       right_gap =
         GetChunksGap(chunks_record->chunk_widths, row) / normalizing_height;
       SEAM *right_seam =
         static_cast<SEAM *>(array_value(chunks_record->splits, row));
       if (debug_level) {
         tprintf("right_gap %g right_seam %g\n",
                 right_gap, right_seam->priority);
       }
       if (right_gap < kMinGap || right_seam->priority > 0.0f) {
         stats->bad_shape = true;
         if (right_gap < kMinGap) stats->bad_fixed_pitch_right_gap = true;
       }
     }
 
     // Impose additional segmentation penalties if blob widths or gaps
     // distribution don't fit a fixed-pitch model.
     // Since we only know the widths and gaps of the path explored so far,
     // the means and variances are computed for the path so far (not
     // considering characters to the right of the last character on the path).
     stats->full_wh_ratio = wh_ratio + right_gap;
     if (parent_stats != NULL) {
       stats->full_wh_ratio_total =
         (parent_stats->full_wh_ratio_total + stats->full_wh_ratio);
       float mean =
         stats->full_wh_ratio_total / static_cast<float>(parent_path_length+1);
       stats->full_wh_ratio_var =
         parent_stats->full_wh_ratio_var + pow(mean-stats->full_wh_ratio, 2);
     } else {
       stats->full_wh_ratio_total = stats->full_wh_ratio;
     }
     if (debug_level) {
       tprintf("full_wh_ratio %g full_wh_ratio_total %g full_wh_ratio_var %g\n",
               stats->full_wh_ratio, stats->full_wh_ratio_total,
               stats->full_wh_ratio_var);
     }
 
     stats->shape_cost =
       FixedPitchWidthCost(wh_ratio, right_gap, end_row, max_char_wh_ratio);
 
     // For some reason Tesseract prefers to treat the whole CJ words
     // as one blob when the initial segmentation is particularly bad.
     // This hack is to avoid favoring such states.
     if (col == 0 && end_row && wh_ratio > max_char_wh_ratio) {
       stats->shape_cost += 10;
     }
     stats->shape_cost += stats->full_wh_ratio_var;
     if (debug_level) tprintf("shape_cost %g\n", stats->shape_cost);
   }
 }

static float tesseract::AssociateUtils::FixedPitchGapCost	(	float	norm_gap,
		bool	end_pos
	)

inlinestatic

Definition at line 143 of file associate.h.

                                                                       {
     return (norm_gap < 0.05 && !end_pos) ? 5.0f : 0.0f;
   }

float tesseract::AssociateUtils::FixedPitchWidthCost	(	float	norm_width,
		float	right_gap,
		bool	end_pos,
		float	max_char_wh_ratio
	)

static

Definition at line 152 of file associate.cpp.

                                                                    {
   float cost = 0.0f;
   if (norm_width > max_char_wh_ratio) cost += norm_width;
   if (norm_width > kMaxFixedPitchCharAspectRatio)
     cost += norm_width * norm_width;  // extra penalty for merging CJK chars
   // Penalize skinny blobs, except for punctuation in the last position.
   if (norm_width+right_gap < 0.5f && !end_pos) {
     cost += 1.0f - (norm_width + right_gap);
   }
   return cost;
 }

static int tesseract::AssociateUtils::GetChunksGap	(	WIDTH_RECORD *	width_record,
		int	last_chunk
	)

inlinestatic

Definition at line 132 of file associate.h.

                                                                              {
     return (last_chunk >= 0 && last_chunk < width_record->num_chars - 1) ?
       width_record->widths[last_chunk * 2 + 1] : 0;
   }

int tesseract::AssociateUtils::GetChunksWidth	(	WIDTH_RECORD *	width_record,
		int	start_blob,
		int	last_blob
	)

static

Definition at line 144 of file associate.cpp.

                                                                   {
   int result = 0;
   for (int x = start_blob * 2; x <= last_blob * 2; x++)
     result += width_record->widths[x];
   return result;
 }

Member Data Documentation

const float tesseract::AssociateUtils::kMaxFixedPitchCharAspectRatio = 2.0f

static

Definition at line 98 of file associate.h.

const float tesseract::AssociateUtils::kMinGap = 0.03f

static

Definition at line 99 of file associate.h.

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

/home/abuild/rpmbuild/BUILD/tesseract-ocr-3.02.02/wordrec/associate.h
/home/abuild/rpmbuild/BUILD/tesseract-ocr-3.02.02/wordrec/associate.cpp

Static Public Member Functions

Static Public Attributes

Detailed Description

Member Function Documentation

Member Data Documentation