tesseract/textord/blkocc.h

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/******************************************************************************
*
* File: blkocc.h (Formerly blockocc.h)
* Description: Block Occupancy routines
* Author: Chris Newton
* Created: Fri Nov 8
* Modified:
* Language: C++
* Package: N/A
* Status: Experimental (Do Not Distribute)
*
* (c) Copyright 1991, Hewlett-Packard Company.
** 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.
*
******************************************************************************/
#ifndef BLKOCC_H
#define BLKOCC_H
#include "varable.h"
#include "polyblob.h"
#include "elst.h"
#include "notdll.h"
#include "notdll.h"
/***************************************************************************
CLASS REGION_OCC
The class REGION_OCC defines a section of outline which exists entirely
within a single region. The only data held is the min and max x limits of
the outline within the region.
REGION_OCCs are held on lists, one list for each region. The lists are
built in sorted order of min x. Overlapping REGION_OCCs are not permitted on
a single list. An overlapping region to be added causes the existing region
to be extended. This extension may result in the following REGION_OCC on the
list overlapping the ammended one. In this case the ammended REGION_OCC is
further extended to include the range of the following one, so that the
following one can be deleted.
****************************************************************************/
class REGION_OCC:public ELIST_LINK
{
public:
float min_x; //Lowest x in region
float max_x; //Highest x in region
INT16 region_type; //Type of crossing
REGION_OCC() {
}; //constructor used
//only in COPIER etc
REGION_OCC( //constructor
float min,
float max,
INT16 region) {
min_x = min;
max_x = max;
region_type = region;
}
};
ELISTIZEH (REGION_OCC)
#define RANGE_IN_BAND( band_max, band_min, range_max, range_min ) \
( ((range_min) >= (band_min)) && ((range_max) < (band_max)) ) ? TRUE : FALSE
/************************************************************************
Adapted from the following procedure so that it can be used in the bands
class in an include file...
BOOL8 range_in_band[
range within band?
INT16 band_max,
INT16 band_min,
INT16 range_max,
INT16 range_min]
{
if ( (range_min >= band_min) && (range_max < band_max) )
return TRUE;
else
return FALSE;
}
***********************************************************************/
#define RANGE_OVERLAPS_BAND( band_max, band_min, range_max, range_min ) \
( ((range_max) >= (band_min)) && ((range_min) < (band_max)) ) ? TRUE : FALSE
/************************************************************************
Adapted from the following procedure so that it can be used in the bands
class in an include file...
BOOL8 range_overlaps_band[
range crosses band?
INT16 band_max,
INT16 band_min,
INT16 range_max,
INT16 range_min]
{
if ( (range_max >= band_min) && (range_min < band_max) )
return TRUE;
else
return FALSE;
}
***********************************************************************/
/**********************************************************************
Bands
-----
BAND 4
--------------------------------
BAND 3
--------------------------------
BAND 2
--------------------------------
BAND 1
Band 0 is the dot band
Each band has an error margin above and below. An outline is not considered to
have significantly changed bands until it has moved out of the error margin.
*************************************************************************/
class BAND
{
public:
INT16 max_max; //upper max
INT16 max; //nominal max
INT16 min_max; //lower max
INT16 max_min; //upper min
INT16 min; //nominal min
INT16 min_min; //lower min
BAND() {
} // constructor
void set( // initialise a band
INT16 new_max_max, // upper max
INT16 new_max, // new nominal max
INT16 new_min_max, // new lower max
INT16 new_max_min, // new upper min
INT16 new_min, // new nominal min
INT16 new_min_min) { // new lower min
max_max = new_max_max;
max = new_max;
min_max = new_min_max;
max_min = new_max_min;
min = new_min;
min_min = new_min_min;
}
BOOL8 in_minimal( //in minimal limits?
float y) { //y value
if ((y >= max_min) && (y < min_max))
return TRUE;
else
return FALSE;
}
BOOL8 in_nominal( //in nominal limits?
float y) { //y value
if ((y >= min) && (y < max))
return TRUE;
else
return FALSE;
}
BOOL8 in_maximal( //in maximal limits?
float y) { //y value
if ((y >= min_min) && (y < max_max))
return TRUE;
else
return FALSE;
}
//overlaps min limits?
BOOL8 range_overlaps_minimal(float y1, //one range limit
float y2) { //other range limit
if (y1 > y2)
return RANGE_OVERLAPS_BAND (min_max, max_min, y1, y2);
else
return RANGE_OVERLAPS_BAND (min_max, max_min, y2, y1);
}
//overlaps nom limits?
BOOL8 range_overlaps_nominal(float y1, //one range limit
float y2) { //other range limit
if (y1 > y2)
return RANGE_OVERLAPS_BAND (max, min, y1, y2);
else
return RANGE_OVERLAPS_BAND (max, min, y2, y1);
}
//overlaps max limits?
BOOL8 range_overlaps_maximal(float y1, //one range limit
float y2) { //other range limit
if (y1 > y2)
return RANGE_OVERLAPS_BAND (max_max, min_min, y1, y2);
else
return RANGE_OVERLAPS_BAND (max_max, min_min, y2, y1);
}
BOOL8 range_in_minimal( //within min limits?
float y1, //one range limit
float y2) { //other range limit
if (y1 > y2)
return RANGE_IN_BAND (min_max, max_min, y1, y2);
else
return RANGE_IN_BAND (min_max, max_min, y2, y1);
}
BOOL8 range_in_nominal( //within nom limits?
float y1, //one range limit
float y2) { //other range limit
if (y1 > y2)
return RANGE_IN_BAND (max, min, y1, y2);
else
return RANGE_IN_BAND (max, min, y2, y1);
}
BOOL8 range_in_maximal( //within max limits?
float y1, //one range limit
float y2) { //other range limit
if (y1 > y2)
return RANGE_IN_BAND (max_max, min_min, y1, y2);
else
return RANGE_IN_BAND (max_max, min_min, y2, y1);
}
};
/* Standard positions */
#define MAX_NUM_BANDS 5
#define UNDEFINED_BAND 99
#define NO_LOWER_LIMIT -9999
#define NO_UPPER_LIMIT 9999
#define DOT_BAND 0
/* Special occupancy code emitted for the 0 region at the end of a word */
#define END_OF_WERD_CODE 255
extern BOOL_VAR_H (blockocc_show_result, FALSE, "Show intermediate results");
extern INT_VAR_H (blockocc_desc_height, 0,
"Descender height after normalisation");
extern INT_VAR_H (blockocc_asc_height, 255,
"Ascender height after normalisation");
extern INT_VAR_H (blockocc_band_count, 4, "Number of bands used");
extern double_VAR_H (textord_underline_threshold, 0.9,
"Fraction of width occupied");
BOOL8 test_underline( //look for underlines
BOOL8 testing_on, //drawing blob
PBLOB *blob, //blob to test
float baseline, //coords of baseline
float xheight //height of line
);
BOOL8 test_underline( //look for underlines
BOOL8 testing_on, //drawing blob
C_BLOB *blob, //blob to test
INT16 baseline, //coords of baseline
INT16 xheight //height of line
);
//project outlines
void horizontal_cblob_projection(C_BLOB *blob, //blob to project
STATS *stats //output
);
void horizontal_coutline_projection( //project outlines
C_OUTLINE *outline, //outline to project
STATS *stats //output
);
void set_bands( //init from varibles
float baseline, //top of bottom band
float xheight //height of split band
);
void block_occ (PBLOB * blob, //blob to do
float occs[] //output histogram
);
//blob to do
void find_transitions(PBLOB *blob, REGION_OCC_LIST *region_occ_list);
void record_region( //add region on list
INT16 band,
float new_min,
float new_max,
INT16 region_type,
REGION_OCC_LIST *region_occ_list);
INT16 find_containing_maximal_band( //find range's band
float y1,
float y2,
BOOL8 *doubly_contained);
void find_significant_line(POLYPT_IT it, INT16 *band);
INT16 find_overlapping_minimal_band( //find range's band
float y1,
float y2);
INT16 find_region_type(INT16 entry_band,
INT16 current_band,
INT16 exit_band,
float entry_x,
float exit_x);
void find_trans_point(POLYPT_IT *pt_it,
INT16 current_band,
INT16 next_band,
FCOORD *transition_pt);
void next_region(POLYPT_IT *start_pt_it,
INT16 start_band,
INT16 *to_band,
float *min_x,
float *max_x,
INT16 *increment,
FCOORD *exit_pt);
INT16 find_band( // find POINT's band
float y);
void compress_region_list( // join open regions
REGION_OCC_LIST *region_occ_list);
void find_fbox(OUTLINE_IT *out_it,
float *min_x,
float *min_y,
float *max_x,
float *max_y);
void maintain_limits(float *min_x, float *max_x, float x);
#endif