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android / platform / external / tesseract / 18bf966e8900e858fa001671e594405603837e35 / . / textord / makerow.cpp
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/**********************************************************************
* File: makerow.cpp (Formerly makerows.c)
* Description: Code to arrange blobs into rows of text.
* Author: Ray Smith
* Created: Mon Sep 21 14:34:48 BST 1992
*
* (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.
*
**********************************************************************/
#include "mfcpch.h"
#ifdef __UNIX__
#include <assert.h>
#endif
#include "stderr.h"
#include "blobbox.h"
#include "lmedsq.h"
#include "statistc.h"
#include "drawtord.h"
#include "blkocc.h"
#include "sortflts.h"
#include "oldbasel.h"
#include "tordmain.h"
#include "underlin.h"
#include "makerow.h"
#include "tprintf.h"
#define EXTERN
EXTERN BOOL_VAR (textord_heavy_nr, FALSE, "Vigorously remove noise");
EXTERN BOOL_VAR (textord_show_initial_rows, FALSE,
"Display row accumulation");
EXTERN BOOL_VAR (textord_show_parallel_rows, FALSE,
"Display page correlated rows");
EXTERN BOOL_VAR (textord_show_expanded_rows, FALSE,
"Display rows after expanding");
EXTERN BOOL_VAR (textord_show_final_rows, FALSE,
"Display rows after final fittin");
EXTERN BOOL_VAR (textord_show_final_blobs, FALSE,
"Display blob bounds after pre-ass");
EXTERN BOOL_VAR (textord_test_landscape, FALSE, "Tests refer to land/port");
EXTERN BOOL_VAR (textord_parallel_baselines, TRUE,
"Force parallel baselines");
EXTERN BOOL_VAR (textord_straight_baselines, FALSE,
"Force straight baselines");
EXTERN BOOL_VAR (textord_quadratic_baselines, FALSE, "Use quadratic splines");
EXTERN BOOL_VAR (textord_old_baselines, TRUE, "Use old baseline algorithm");
EXTERN BOOL_VAR (textord_old_xheight, TRUE, "Use old xheight algorithm");
EXTERN BOOL_VAR (textord_fix_xheight_bug, TRUE, "Use spline baseline");
EXTERN BOOL_VAR (textord_fix_makerow_bug, TRUE, "Prevent multiple baselines");
EXTERN BOOL_VAR (textord_row_xheights, FALSE, "Use row height policy");
EXTERN BOOL_VAR (textord_block_xheights, TRUE, "Use block height policy");
EXTERN BOOL_VAR (textord_xheight_tweak, FALSE, "New min condition on height");
EXTERN BOOL_VAR (textord_cblob_blockocc, TRUE,
"Use new projection for underlines");
EXTERN BOOL_VAR (textord_debug_xheights, FALSE, "Test xheight algorithms");
EXTERN BOOL_VAR (textord_biased_skewcalc, TRUE,
"Bias skew estimates with line length");
EXTERN BOOL_VAR (textord_interpolating_skew, TRUE, "Interpolate across gaps");
EXTERN INT_VAR (textord_skewsmooth_offset, 2, "For smooth factor");
EXTERN INT_VAR (textord_skewsmooth_offset2, 1, "For smooth factor");
EXTERN INT_VAR (textord_test_x, -1, "coord of test pt");
EXTERN INT_VAR (textord_test_y, -1, "coord of test pt");
EXTERN INT_VAR (textord_min_blobs_in_row, 4,
"Min blobs before gradient counted");
EXTERN INT_VAR (textord_spline_minblobs, 8,
"Min blobs in each spline segment");
EXTERN INT_VAR (textord_spline_medianwin, 6,
"Size of window for spline segmentation");
EXTERN INT_VAR (textord_min_xheight, 10, "Min credible pixel xheight");
EXTERN double_VAR (textord_spline_shift_fraction, 0.02,
"Fraction of line spacing for quad");
EXTERN double_VAR (textord_spline_outlier_fraction, 0.1,
"Fraction of line spacing for outlier");
EXTERN double_VAR (textord_skew_ile, 0.5, "Ile of gradients for page skew");
EXTERN double_VAR (textord_skew_lag, 0.01,
"Lag for skew on row accumulation");
EXTERN double_VAR (textord_linespace_iqrlimit, 0.2,
"Max iqr/median for linespace");
EXTERN double_VAR (textord_width_limit, 8, "Max width of blobs to make rows");
EXTERN double_VAR (textord_chop_width, 1.5, "Max width before chopping");
EXTERN double_VAR (textord_expansion_factor, 1.0,
"Factor to expand rows by in expand_rows");
EXTERN double_VAR (textord_overlap_x, 0.5,
"Fraction of linespace for good overlap");
EXTERN double_VAR (textord_merge_desc, 0.25,
"Fraction of linespace for desc drop");
EXTERN double_VAR (textord_merge_x, 0.5,
"Fraction of linespace for x height");
EXTERN double_VAR (textord_merge_asc, 0.25,
"Fraction of linespace for asc height");
EXTERN double_VAR (textord_minxh, 0.25,
"fraction of linesize for min xheight");
EXTERN double_VAR (textord_min_linesize, 1.25,
"* blob height for initial linesize");
EXTERN double_VAR (textord_excess_blobsize, 1.3,
"New row made if blob makes row this big");
EXTERN double_VAR (textord_occupancy_threshold, 0.4,
"Fraction of neighbourhood");
EXTERN double_VAR (textord_underline_width, 2.0,
"Multiple of line_size for underline");
EXTERN double_VAR (textord_xheight_mode_fraction, 0.4,
"Min pile height to make xheight");
EXTERN double_VAR (textord_ascheight_mode_fraction, 0.15,
"Min pile height to make ascheight");
EXTERN double_VAR (textord_ascx_ratio_min, 1.2, "Min cap/xheight");
EXTERN double_VAR (textord_ascx_ratio_max, 1.7, "Max cap/xheight");
EXTERN double_VAR (textord_descx_ratio_min, 0.15, "Min desc/xheight");
EXTERN double_VAR (textord_descx_ratio_max, 0.6, "Max desc/xheight");
EXTERN double_VAR (textord_xheight_error_margin, 0.1, "Accepted variation");
#define MAX_HEIGHT_MODES 12
/**********************************************************************
* make_single_row
*
* Arrange the blobs into a single row.
**********************************************************************/
float make_single_row(ICOORD page_tr, TO_BLOCK* block, TO_BLOCK_LIST* blocks) {
BLOBNBOX_IT blob_it = &block->blobs;
TO_ROW_IT row_it = block->get_rows();
// Include all the small blobs and large blobs.
blob_it.add_list_after(&block->small_blobs);
blob_it.add_list_after(&block->noise_blobs);
blob_it.add_list_after(&block->large_blobs);
blob_it.sort(blob_x_order);
blob_it.move_to_first();
TO_ROW* row = NULL;
// Add all the blobs to a single TO_ROW.
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
BLOBNBOX* blob = blob_it.extract();
int top = blob->bounding_box().top();
int bottom = blob->bounding_box().bottom();
if (row == NULL) {
row = new TO_ROW(blob, top, bottom, block->line_size);
row_it.add_before_then_move(row);
} else {
row->add_blob(blob, top, bottom, block->line_size);
}
}
// Fit an LMS line to the row.
for (row_it.mark_cycle_pt(); !row_it.cycled_list(); row_it.forward())
fit_lms_line(row_it.data());
float gradient;
float fit_error;
// Compute the skew based on the fitted line.
compute_page_skew(blocks, gradient, fit_error);
FCOORD rotation(1.0f, 0.0f);
// Associate i dots and other diacriticals with the appropriate blobs.
pre_associate_blobs(page_tr, block, rotation, false);
int block_edge = block->block->bounding_box().left();
fit_parallel_rows(block, gradient, rotation, block_edge, false);
// Make the curved baselines and setup some key block members.
make_spline_rows(block, gradient, rotation, block_edge, false);
return gradient;
}
/**********************************************************************
* make_rows
*
* Arrange the blobs into rows.
**********************************************************************/
float make_rows( //make rows
ICOORD page_tr, //top right
BLOCK_LIST *blocks, //block list
TO_BLOCK_LIST *land_blocks, //rotated for landscape
TO_BLOCK_LIST *port_blocks //output list
) {
float port_m; //global skew
float port_err; //global noise
// float land_m; //global skew
// float land_err; //global noise
TO_BLOCK_IT block_it; //iterator
//don't do landscape for now
// block_it.set_to_list(land_blocks);
// for (block_it.mark_cycle_pt();!block_it.cycled_list();block_it.forward())
// make_initial_textrows(page_tr,block_it.data(),FCOORD(0,-1),
// (BOOL8)textord_test_landscape);
block_it.set_to_list (port_blocks);
for (block_it.mark_cycle_pt (); !block_it.cycled_list ();
block_it.forward ())
make_initial_textrows (page_tr, block_it.data (), FCOORD (1.0f, 0.0f),
!(BOOL8) textord_test_landscape);
//compute globally
compute_page_skew(port_blocks, port_m, port_err);
// compute_page_skew(land_blocks,land_m,land_err); //compute globally
// tprintf("Portrait skew gradient=%g, error=%g.\n",
// port_m,port_err);
// tprintf("Landscape skew gradient=%g, error=%g.\n",
// land_m,land_err);
block_it.set_to_list (port_blocks);
for (block_it.mark_cycle_pt (); !block_it.cycled_list ();
block_it.forward ()) {
cleanup_rows (page_tr, block_it.data (), port_m, FCOORD (1.0f, 0.0f),
block_it.data ()->block->bounding_box ().left (),
!(BOOL8) textord_test_landscape);
}
block_it.set_to_list (land_blocks);
// for (block_it.mark_cycle_pt();!block_it.cycled_list();block_it.forward())
// {
// cleanup_rows(page_tr,block_it.data(),land_m,FCOORD(0,-1),
// -block_it.data()->block->bounding_box().top(),
// (BOOL8)textord_test_landscape);
// }
return port_m; //global skew
}
/**********************************************************************
* make_initial_textrows
*
* Arrange the good blobs into rows of text.
**********************************************************************/
void make_initial_textrows( //find lines
ICOORD page_tr,
TO_BLOCK *block, //block to do
FCOORD rotation, //for drawing
BOOL8 testing_on //correct orientation
) {
TO_ROW_IT row_it = block->get_rows ();
#ifndef GRAPHICS_DISABLED
ScrollView::Color colour; //of row
if (textord_show_initial_rows && testing_on) {
if (to_win == NULL)
create_to_win(page_tr);
}
#endif
//guess skew
assign_blobs_to_rows (block, NULL, 0, TRUE, TRUE, textord_show_initial_rows && testing_on);
row_it.move_to_first ();
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ())
fit_lms_line (row_it.data ());
#ifndef GRAPHICS_DISABLED
if (textord_show_initial_rows && testing_on) {
colour = ScrollView::RED;
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
plot_to_row (row_it.data (), colour, rotation);
colour = (ScrollView::Color) (colour + 1);
if (colour > ScrollView::MAGENTA)
colour = ScrollView::RED;
}
}
#endif
}
/**********************************************************************
* fit_lms_line
*
* Fit an LMS line to a row.
**********************************************************************/
void fit_lms_line( //sort function
TO_ROW *row //row to fit
) {
float m, c; //fitted line
TBOX box; //blob box
LMS lms (row->blob_list ()->length ());
//blobs
BLOBNBOX_IT blob_it = row->blob_list ();
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list (); blob_it.forward ()) {
box = blob_it.data ()->bounding_box ();
lms.add (FCOORD ((box.left () + box.right ()) / 2.0, box.bottom ()));
}
lms.fit (m, c);
row->set_line (m, c, lms.error ());
}
/**********************************************************************
* compute_page_skew
*
* Compute the skew over a full page by averaging the gradients over
* all the lines. Get the error of the same row.
**********************************************************************/
void compute_page_skew( //get average gradient
TO_BLOCK_LIST *blocks, //list of blocks
float &page_m, //average gradient
float &page_err //average error
) {
inT32 row_count; //total rows
inT32 blob_count; //total_blobs
inT32 row_err; //integer error
float *gradients; //of rows
float *errors; //of rows
inT32 row_index; //of total
TO_ROW *row; //current row
TO_BLOCK_IT block_it = blocks; //iterator
TO_ROW_IT row_it;
row_count = 0;
blob_count = 0;
for (block_it.mark_cycle_pt (); !block_it.cycled_list ();
block_it.forward ()) {
row_count += block_it.data ()->get_rows ()->length ();
//count up rows
row_it.set_to_list (block_it.data ()->get_rows ());
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ())
blob_count += row_it.data ()->blob_list ()->length ();
}
if (row_count == 0) {
page_m = 0.0f;
page_err = 0.0f;
return;
}
gradients = (float *) alloc_mem (blob_count * sizeof (float));
//get mem
errors = (float *) alloc_mem (blob_count * sizeof (float));
if (gradients == NULL || errors == NULL)
MEMORY_OUT.error ("compute_page_skew", ABORT, NULL);
row_index = 0;
for (block_it.mark_cycle_pt (); !block_it.cycled_list ();
block_it.forward ()) {
row_it.set_to_list (block_it.data ()->get_rows ());
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
row = row_it.data ();
blob_count = row->blob_list ()->length ();
row_err = (inT32) ceil (row->line_error ());
if (row_err <= 0)
row_err = 1;
if (textord_biased_skewcalc) {
blob_count /= row_err;
for (blob_count /= row_err; blob_count > 0; blob_count--) {
gradients[row_index] = row->line_m ();
errors[row_index] = row->line_error ();
row_index++;
}
}
else if (blob_count >= textord_min_blobs_in_row) {
//get gradient
gradients[row_index] = row->line_m ();
errors[row_index] = row->line_error ();
row_index++;
}
}
}
if (row_index == 0) {
//desperate
for (block_it.mark_cycle_pt (); !block_it.cycled_list ();
block_it.forward ()) {
row_it.set_to_list (block_it.data ()->get_rows ());
for (row_it.mark_cycle_pt (); !row_it.cycled_list ();
row_it.forward ()) {
row = row_it.data ();
gradients[row_index] = row->line_m ();
errors[row_index] = row->line_error ();
row_index++;
}
}
}
row_count = row_index;
row_index = choose_nth_item ((inT32) (row_count * textord_skew_ile),
gradients, row_count);
page_m = gradients[row_index];
row_index = choose_nth_item ((inT32) (row_count * textord_skew_ile),
errors, row_count);
page_err = errors[row_index];
free_mem(gradients);
free_mem(errors);
}
const double kNoiseSize = 0.5; // Fraction of xheight.
const int kMinSize = 8; // Min pixels to be xheight.
// Return true if the dot looks like it is part of the i.
// Doesn't work for any other diacritical.
static bool dot_of_i(BLOBNBOX* dot, BLOBNBOX* i, TO_ROW* row) {
const TBOX& ibox = i->bounding_box();
const TBOX& dotbox = dot->bounding_box();
// Must overlap horizontally by enough and be high enough.
int overlap = MIN(dotbox.right(), ibox.right()) -
MAX(dotbox.left(), ibox.left());
if (ibox.height() <= 2 * dotbox.height() ||
(overlap * 2 < ibox.width() && overlap < dotbox.width()))
return false;
// If the i is tall and thin then it is good.
if (ibox.height() > ibox.width() * 2)
return true; // The i or ! must be tall and thin.
// It might still be tall and thin, but it might be joined to something.
// So search the outline for a piece of large height close to the edges
// of the dot.
const double kHeightFraction = 0.6;
double target_height = MIN(dotbox.bottom(), ibox.top());
target_height -= row->line_m()*dotbox.left() + row->line_c();
target_height *= kHeightFraction;
int left_min = dotbox.left() - dotbox.width();
int middle = (dotbox.left() + dotbox.right())/2;
int right_max = dotbox.right() + dotbox.width();
int left_miny = 0;
int left_maxy = 0;
int right_miny = 0;
int right_maxy = 0;
bool found_left = false;
bool found_right = false;
bool in_left = false;
bool in_right = false;
C_BLOB* blob = i->cblob();
C_OUTLINE_IT o_it = blob->out_list();
for (o_it.mark_cycle_pt(); !o_it.cycled_list(); o_it.forward()) {
C_OUTLINE* outline = o_it.data();
int length = outline->pathlength();
ICOORD pos = outline->start_pos();
for (int step = 0; step < length; pos += outline->step(step++)) {
int x = pos.x();
int y = pos.y();
if (x >= left_min && x < middle && !found_left) {
// We are in the left part so find min and max y.
if (in_left) {
if (y > left_maxy) left_maxy = y;
if (y < left_miny) left_miny = y;
} else {
left_maxy = left_miny = y;
in_left = true;
}
} else if (in_left) {
// We just left the left so look for size.
if (left_maxy - left_miny > target_height) {
if (found_right)
return true;
found_left = true;
}
in_left = false;
}
if (x <= right_max && x > middle && !found_right) {
// We are in the right part so find min and max y.
if (in_right) {
if (y > right_maxy) right_maxy = y;
if (y < right_miny) right_miny = y;
} else {
right_maxy = right_miny = y;
in_right = true;
}
} else if (in_right) {
// We just left the right so look for size.
if (right_maxy - right_miny > target_height) {
if (found_left)
return true;
found_right = true;
}
in_right = false;
}
}
}
return false;
}
static void vigorous_noise_removal(TO_BLOCK* block) {
TO_ROW_IT row_it = block->get_rows ();
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
TO_ROW* row = row_it.data();
BLOBNBOX_IT b_it = row->blob_list();
// Estimate the xheight on the row.
int max_height = 0;
for (b_it.mark_cycle_pt(); !b_it.cycled_list(); b_it.forward()) {
BLOBNBOX* blob = b_it.data();
if (blob->bounding_box().height() > max_height)
max_height = blob->bounding_box().height();
}
STATS hstats(0, max_height + 1);
for (b_it.mark_cycle_pt(); !b_it.cycled_list(); b_it.forward()) {
BLOBNBOX* blob = b_it.data();
int height = blob->bounding_box().height();
if (height >= kMinSize)
hstats.add(blob->bounding_box().height(), 1);
}
float xheight = hstats.median();
// Delete small objects.
BLOBNBOX* prev = NULL;
for (b_it.mark_cycle_pt(); !b_it.cycled_list(); b_it.forward()) {
BLOBNBOX* blob = b_it.data();
const TBOX& box = blob->bounding_box();
if (box.height() < kNoiseSize * xheight) {
// Small so delete unless it looks like an i dot.
if (prev != NULL) {
if (dot_of_i(blob, prev, row))
continue; // Looks OK.
}
if (!b_it.at_last()) {
BLOBNBOX* next = b_it.data_relative(1);
if (dot_of_i(blob, next, row))
continue; // Looks OK.
}
// It might be noise so get rid of it.
if (blob->blob() != NULL)
delete blob->blob();
if (blob->cblob() != NULL)
delete blob->cblob();
delete b_it.extract();
} else {
prev = blob;
}
}
}
}
/**********************************************************************
* cleanup_rows
*
* Remove overlapping rows and fit all the blobs to what's left.
**********************************************************************/
void cleanup_rows( //find lines
ICOORD page_tr, //top right
TO_BLOCK *block, //block to do
float gradient, //gradient to fit
FCOORD rotation, //for drawing
inT32 block_edge, //edge of block
BOOL8 testing_on //correct orientation
) {
//iterators
BLOBNBOX_IT blob_it = &block->blobs;
TO_ROW_IT row_it = block->get_rows ();
#ifndef GRAPHICS_DISABLED
if (textord_show_parallel_rows && testing_on) {
if (to_win == NULL)
create_to_win(page_tr);
}
#endif
//get row coords
fit_parallel_rows(block,
gradient,
rotation,
block_edge,
textord_show_parallel_rows &&testing_on);
delete_non_dropout_rows(block,
gradient,
rotation,
block_edge,
textord_show_parallel_rows &&testing_on);
expand_rows(page_tr, block, gradient, rotation, block_edge, testing_on);
blob_it.set_to_list (&block->blobs);
row_it.set_to_list (block->get_rows ());
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ())
blob_it.add_list_after (row_it.data ()->blob_list ());
//give blobs back
assign_blobs_to_rows (block, &gradient, 1, FALSE, FALSE, FALSE);
//now new rows must be genuine
blob_it.set_to_list (&block->blobs);
blob_it.add_list_after (&block->large_blobs);
assign_blobs_to_rows (block, &gradient, 2, TRUE, TRUE, FALSE);
//safe to use big ones now
blob_it.set_to_list (&block->blobs);
//throw all blobs in
blob_it.add_list_after (&block->noise_blobs);
blob_it.add_list_after (&block->small_blobs);
assign_blobs_to_rows (block, &gradient, 3, FALSE, FALSE, FALSE);
//no rows for noise
row_it.set_to_list (block->get_rows ());
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ())
row_it.data ()->blob_list ()->sort (blob_x_order);
fit_parallel_rows(block, gradient, rotation, block_edge, FALSE);
if (textord_heavy_nr) {
vigorous_noise_removal(block);
}
separate_underlines(block, gradient, rotation, testing_on);
pre_associate_blobs(page_tr, block, rotation, testing_on);
#ifndef GRAPHICS_DISABLED
if (textord_show_final_rows && testing_on) {
if (to_win == NULL)
create_to_win(page_tr);
}
#endif
fit_parallel_rows(block, gradient, rotation, block_edge, FALSE);
// textord_show_final_rows && testing_on);
make_spline_rows(block,
gradient,
rotation,
block_edge,
textord_show_final_rows &&testing_on);
if (!textord_old_xheight || !textord_old_baselines)
compute_block_xheight(block, gradient);
if (textord_restore_underlines)
//fix underlines
restore_underlined_blobs(block);
#ifndef GRAPHICS_DISABLED
if (textord_show_final_rows && testing_on) {
plot_blob_list (to_win, &block->blobs,
ScrollView::MAGENTA, ScrollView::WHITE);
//show discarded blobs
plot_blob_list (to_win, &block->underlines,
ScrollView::YELLOW, ScrollView::CORAL);
}
if (textord_show_final_rows && testing_on && block->blobs.length () > 0)
tprintf ("%d blobs discarded as noise\n", block->blobs.length ());
if (textord_show_final_rows && testing_on) {
draw_meanlines(block, gradient, block_edge, ScrollView::WHITE, rotation);
}
#endif
}
/**********************************************************************
* delete_non_dropout_rows
*
* Compute the linespacing and offset.
**********************************************************************/
void delete_non_dropout_rows( //find lines
TO_BLOCK *block, //block to do
float gradient, //global skew
FCOORD rotation, //deskew vector
inT32 block_edge, //left edge
BOOL8 testing_on //correct orientation
) {
TBOX block_box; //deskewed block
inT32 *deltas; //change in occupation
inT32 *occupation; //of pixel coords
inT32 max_y; //in block
inT32 min_y;
inT32 line_index; //of scan line
inT32 line_count; //no of scan lines
inT32 distance; //to drop-out
inT32 xleft; //of block
inT32 ybottom; //of block
TO_ROW *row; //current row
TO_ROW_IT row_it = block->get_rows ();
BLOBNBOX_IT blob_it = &block->blobs;
if (row_it.length () == 0)
return; //empty block
block_box = deskew_block_coords (block, gradient);
xleft = block->block->bounding_box ().left ();
ybottom = block->block->bounding_box ().bottom ();
min_y = block_box.bottom () - 1;
max_y = block_box.top () + 1;
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
line_index = (inT32) floor (row_it.data ()->intercept ());
if (line_index <= min_y)
min_y = line_index - 1;
if (line_index >= max_y)
max_y = line_index + 1;
}
line_count = max_y - min_y + 1;
if (line_count <= 0)
return; //empty block
deltas = (inT32 *) alloc_mem (line_count * sizeof (inT32));
occupation = (inT32 *) alloc_mem (line_count * sizeof (inT32));
if (deltas == NULL || occupation == NULL)
MEMORY_OUT.error ("compute_line_spacing", ABORT, NULL);
compute_line_occupation(block, gradient, min_y, max_y, occupation, deltas);
compute_occupation_threshold ((inT32)
ceil (block->line_spacing *
(textord_merge_desc +
textord_merge_asc)),
(inT32) ceil (block->line_spacing *
(textord_merge_x +
textord_merge_asc)),
max_y - min_y + 1, occupation, deltas);
#ifndef GRAPHICS_DISABLED
if (testing_on) {
draw_occupation(xleft, ybottom, min_y, max_y, occupation, deltas);
}
#endif
compute_dropout_distances(occupation, deltas, line_count);
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
row = row_it.data ();
line_index = (inT32) floor (row->intercept ());
distance = deltas[line_index - min_y];
if (find_best_dropout_row (row, distance, block->line_spacing / 2,
line_index, &row_it, testing_on)) {
#ifndef GRAPHICS_DISABLED
if (testing_on)
plot_parallel_row(row, gradient, block_edge,
ScrollView::WHITE, rotation);
#endif
blob_it.add_list_after (row_it.data ()->blob_list ());
delete row_it.extract (); //too far away
}
}
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
blob_it.add_list_after (row_it.data ()->blob_list ());
}
free_mem(deltas);
free_mem(occupation);
}
/**********************************************************************
* find_best_dropout_row
*
* Delete this row if it has a neighbour with better dropout characteristics.
* TRUE is returned if the row should be deleted.
**********************************************************************/
BOOL8 find_best_dropout_row( //find neighbours
TO_ROW *row, //row to test
inT32 distance, //dropout dist
float dist_limit, //threshold distance
inT32 line_index, //index of row
TO_ROW_IT *row_it, //current position
BOOL8 testing_on //correct orientation
) {
inT32 next_index; //of neigbouring row
inT32 row_offset; //from current row
inT32 abs_dist; //absolute distance
inT8 row_inc; //increment to row_index
TO_ROW *next_row; //nextious row
if (testing_on)
tprintf ("Row at %g(%g), dropout dist=%d,",
row->intercept (), row->parallel_c (), distance);
if (distance < 0) {
row_inc = 1;
abs_dist = -distance;
}
else {
row_inc = -1;
abs_dist = distance;
}
if (abs_dist > dist_limit) {
if (testing_on) {
tprintf (" too far - deleting\n");
}
return TRUE;
}
if ((distance < 0 && !row_it->at_last ())
|| (distance >= 0 && !row_it->at_first ())) {
row_offset = row_inc;
do {
next_row = row_it->data_relative (row_offset);
next_index = (inT32) floor (next_row->intercept ());
if ((distance < 0
&& next_index < line_index
&& next_index > line_index + distance + distance)
|| (distance >= 0
&& next_index > line_index
&& next_index < line_index + distance + distance)) {
if (testing_on) {
tprintf (" nearer neighbour (%d) at %g\n",
line_index + distance - next_index,
next_row->intercept ());
}
return TRUE; //other is nearer
}
else if (next_index == line_index
|| next_index == line_index + distance + distance) {
if (row->believability () <= next_row->believability ()) {
if (testing_on) {
tprintf (" equal but more believable at %g (%g/%g)\n",
next_row->intercept (),
row->believability (),
next_row->believability ());
}
return TRUE; //other is more believable
}
}
row_offset += row_inc;
}
while ((next_index == line_index
|| next_index == line_index + distance + distance)
&& row_offset < row_it->length ());
if (testing_on)
tprintf (" keeping\n");
}
return FALSE;
}
/**********************************************************************
* deskew_block_coords
*
* Compute the bounding box of all the blobs in the block
* if they were deskewed without actually doing it.
**********************************************************************/
TBOX deskew_block_coords( //block box
TO_BLOCK *block, //block to do
float gradient //global skew
) {
TBOX result; //block bounds
TBOX blob_box; //of block
FCOORD rotation; //deskew vector
float length; //of gradient vector
TO_ROW_IT row_it = block->get_rows ();
TO_ROW *row; //current row
BLOBNBOX *blob; //current blob
BLOBNBOX_IT blob_it; //iterator
length = sqrt (gradient * gradient + 1);
rotation = FCOORD (1 / length, -gradient / length);
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
row = row_it.data ();
blob_it.set_to_list (row->blob_list ());
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
blob_it.forward ()) {
blob = blob_it.data ();
blob_box = blob->bounding_box ();
blob_box.rotate (rotation);//de-skew it
result += blob_box;
}
}
return result;
}
/**********************************************************************
* compute_line_occupation
*
* Compute the pixel projection back on the y axis given the global
* skew. Also compute the 1st derivative.
**********************************************************************/
void compute_line_occupation( //project blobs
TO_BLOCK *block, //block to do
float gradient, //global skew
inT32 min_y, //min coord in block
inT32 max_y, //in block
inT32 *occupation, //output projection
inT32 *deltas //derivative
) {
inT32 line_count; //maxy-miny+1
inT32 line_index; //of scan line
int index; //array index for daft compilers
float top, bottom; //coords of blob
inT32 width; //of blob
TO_ROW *row; //current row
TO_ROW_IT row_it = block->get_rows ();
BLOBNBOX *blob; //current blob
BLOBNBOX_IT blob_it; //iterator
float length; //of skew vector
TBOX blob_box; //bounding box
FCOORD rotation; //inverse of skew
line_count = max_y - min_y + 1;
length = sqrt (gradient * gradient + 1);
rotation = FCOORD (1 / length, -gradient / length);
for (line_index = 0; line_index < line_count; line_index++)
deltas[line_index] = 0;
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
row = row_it.data ();
blob_it.set_to_list (row->blob_list ());
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
blob_it.forward ()) {
blob = blob_it.data ();
blob_box = blob->bounding_box ();
blob_box.rotate (rotation);//de-skew it
top = blob_box.top ();
bottom = blob_box.bottom ();
width =
(inT32) floor ((FLOAT32) (blob_box.right () - blob_box.left ()));
if ((inT32) floor (bottom) < min_y
|| (inT32) floor (bottom) - min_y >= line_count)
fprintf (stderr,
"Bad y coord of bottom, " INT32FORMAT "(" INT32FORMAT ","
INT32FORMAT ")\n", (inT32) floor (bottom), min_y, max_y);
//count transitions
index = (inT32) floor (bottom) - min_y;
deltas[index] += width;
if ((inT32) floor (top) < min_y
|| (inT32) floor (top) - min_y >= line_count)
fprintf (stderr,
"Bad y coord of top, " INT32FORMAT "(" INT32FORMAT ","
INT32FORMAT ")\n", (inT32) floor (top), min_y, max_y);
index = (inT32) floor (top) - min_y;
deltas[index] -= width;
}
}
occupation[0] = deltas[0];
for (line_index = 1; line_index < line_count; line_index++)
occupation[line_index] = occupation[line_index - 1] + deltas[line_index];
}
/**********************************************************************
* compute_occupation_threshold
*
* Compute thresholds for textline or not for the occupation array.
**********************************************************************/
void compute_occupation_threshold( //project blobs
inT32 low_window, //below result point
inT32 high_window, //above result point
inT32 line_count, //array sizes
inT32 *occupation, //input projection
inT32 *thresholds //output thresholds
) {
inT32 line_index; //of thresholds line
inT32 low_index; //in occupation
inT32 high_index; //in occupation
inT32 sum; //current average
inT32 divisor; //to get thresholds
inT32 min_index; //of min occ
inT32 min_occ; //min in locality
inT32 test_index; //for finding min
divisor =
(inT32) ceil ((low_window + high_window) / textord_occupancy_threshold);
if (low_window + high_window < line_count) {
for (sum = 0, high_index = 0; high_index < low_window; high_index++)
sum += occupation[high_index];
for (low_index = 0; low_index < high_window; low_index++, high_index++)
sum += occupation[high_index];
min_occ = occupation[0];
min_index = 0;
for (test_index = 1; test_index < high_index; test_index++) {
if (occupation[test_index] <= min_occ) {
min_occ = occupation[test_index];
min_index = test_index; //find min in region
}
}
for (line_index = 0; line_index < low_window; line_index++)
thresholds[line_index] = (sum - min_occ) / divisor + min_occ;
//same out to end
for (low_index = 0; high_index < line_count; low_index++, high_index++) {
sum -= occupation[low_index];
sum += occupation[high_index];
if (occupation[high_index] <= min_occ) {
//find min in region
min_occ = occupation[high_index];
min_index = high_index;
}
//lost min from region
if (min_index <= low_index) {
min_occ = occupation[low_index + 1];
min_index = low_index + 1;
for (test_index = low_index + 2; test_index <= high_index;
test_index++) {
if (occupation[test_index] <= min_occ) {
min_occ = occupation[test_index];
//find min in region
min_index = test_index;
}
}
}
thresholds[line_index++] = (sum - min_occ) / divisor + min_occ;
}
}
else {
min_occ = occupation[0];
min_index = 0;
for (sum = 0, low_index = 0; low_index < line_count; low_index++) {
if (occupation[low_index] < min_occ) {
min_occ = occupation[low_index];
min_index = low_index;
}
sum += occupation[low_index];
}
line_index = 0;
}
for (; line_index < line_count; line_index++)
thresholds[line_index] = (sum - min_occ) / divisor + min_occ;
//same out to end
}
/**********************************************************************
* compute_dropout_distances
*
* Compute the distance from each coordinate to the nearest dropout.
**********************************************************************/
void compute_dropout_distances( //project blobs
inT32 *occupation, //input projection
inT32 *thresholds, //output thresholds
inT32 line_count //array sizes
) {
inT32 line_index; //of thresholds line
inT32 distance; //from prev dropout
inT32 next_dist; //to next dropout
inT32 back_index; //for back filling
inT32 prev_threshold; //before overwrite
distance = -line_count;
line_index = 0;
do {
do {
distance--;
prev_threshold = thresholds[line_index];
//distance from prev
thresholds[line_index] = distance;
line_index++;
}
while (line_index < line_count
&& (occupation[line_index] < thresholds[line_index]
|| occupation[line_index - 1] >= prev_threshold));
if (line_index < line_count) {
back_index = line_index - 1;
next_dist = 1;
while (next_dist < -distance && back_index >= 0) {
thresholds[back_index] = next_dist;
back_index--;
next_dist++;
distance++;
}
distance = 1;
}
}
while (line_index < line_count);
}
/**********************************************************************
* expand_rows
*
* Expand each row to the least of its allowed size and touching its
* neighbours. If the expansion would entirely swallow a neighbouring row
* then do so.
**********************************************************************/
void expand_rows( //find lines
ICOORD page_tr, //top right
TO_BLOCK *block, //block to do
float gradient, //gradient to fit
FCOORD rotation, //for drawing
inT32 block_edge, //edge of block
BOOL8 testing_on //correct orientation
) {
BOOL8 swallowed_row; //eaten a neighbour
float y_max, y_min; //new row limits
float y_bottom, y_top; //allowed limits
TO_ROW *test_row; //next row
TO_ROW *row; //current row
//iterators
BLOBNBOX_IT blob_it = &block->blobs;
TO_ROW_IT row_it = block->get_rows ();
#ifndef GRAPHICS_DISABLED
if (textord_show_expanded_rows && testing_on) {
if (to_win == NULL)
create_to_win(page_tr);
}
#endif
adjust_row_limits(block); //shift min,max.
if (textord_new_initial_xheight) {
if (block->get_rows ()->length () == 0)
return;
compute_row_stats(block, textord_show_expanded_rows &&testing_on);
}
assign_blobs_to_rows (block, &gradient, 4, TRUE, FALSE, FALSE);
//get real membership
if (block->get_rows ()->length () == 0)
return;
fit_parallel_rows(block,
gradient,
rotation,
block_edge,
textord_show_expanded_rows &&testing_on);
if (!textord_new_initial_xheight)
compute_row_stats(block, textord_show_expanded_rows &&testing_on);
row_it.move_to_last ();
do {
row = row_it.data ();
y_max = row->max_y (); //get current limits
y_min = row->min_y ();
y_bottom = row->intercept () - block->line_size * textord_expansion_factor *
textord_merge_desc;
y_top = row->intercept () + block->line_size * textord_expansion_factor *
(textord_merge_x + textord_merge_asc);
if (y_min > y_bottom) { //expansion allowed
if (textord_show_expanded_rows && testing_on)
tprintf("Expanding bottom of row at %f from %f to %f\n",
row->intercept(), y_min, y_bottom);
//expandable
swallowed_row = TRUE;
while (swallowed_row && !row_it.at_last ()) {
swallowed_row = FALSE;
//get next one
test_row = row_it.data_relative (1);
//overlaps space
if (test_row->max_y () > y_bottom) {
if (test_row->min_y () > y_bottom) {
if (textord_show_expanded_rows && testing_on)
tprintf("Eating row below at %f\n", test_row->intercept());
row_it.forward ();
#ifndef GRAPHICS_DISABLED
if (textord_show_expanded_rows && testing_on)
plot_parallel_row(test_row,
gradient,
block_edge,
ScrollView::WHITE,
rotation);
#endif
blob_it.set_to_list (row->blob_list ());
blob_it.add_list_after (test_row->blob_list ());
//swallow complete row
delete row_it.extract ();
row_it.backward ();
swallowed_row = TRUE;
}
else if (test_row->max_y () < y_min) {
//shorter limit
y_bottom = test_row->max_y ();
if (textord_show_expanded_rows && testing_on)
tprintf("Truncating limit to %f due to touching row at %f\n",
y_bottom, test_row->intercept());
}
else {
y_bottom = y_min; //can't expand it
if (textord_show_expanded_rows && testing_on)
tprintf("Not expanding limit beyond %f due to touching row at %f\n",
y_bottom, test_row->intercept());
}
}
}
y_min = y_bottom; //expand it
}
if (y_max < y_top) { //expansion allowed
if (textord_show_expanded_rows && testing_on)
tprintf("Expanding top of row at %f from %f to %f\n",
row->intercept(), y_max, y_top);
swallowed_row = TRUE;
while (swallowed_row && !row_it.at_first ()) {
swallowed_row = FALSE;
//get one above
test_row = row_it.data_relative (-1);
if (test_row->min_y () < y_top) {
if (test_row->max_y () < y_top) {
if (textord_show_expanded_rows && testing_on)
tprintf("Eating row above at %f\n", test_row->intercept());
row_it.backward ();
blob_it.set_to_list (row->blob_list ());
#ifndef GRAPHICS_DISABLED
if (textord_show_expanded_rows && testing_on)
plot_parallel_row(test_row,
gradient,
block_edge,
ScrollView::WHITE,
rotation);
#endif
blob_it.add_list_after (test_row->blob_list ());
//swallow complete row
delete row_it.extract ();
row_it.forward ();
swallowed_row = TRUE;
}
else if (test_row->min_y () < y_max) {
//shorter limit
y_top = test_row->min_y ();
if (textord_show_expanded_rows && testing_on)
tprintf("Truncating limit to %f due to touching row at %f\n",
y_top, test_row->intercept());
}
else {
y_top = y_max; //can't expand it
if (textord_show_expanded_rows && testing_on)
tprintf("Not expanding limit beyond %f due to touching row at %f\n",
y_top, test_row->intercept());
}
}
}
y_max = y_top;
}
//new limits
row->set_limits (y_min, y_max);
row_it.backward ();
}
while (!row_it.at_last ());
}
/**********************************************************************
* adjust_row_limits
*
* Change the limits of rows to suit the default fractions.
**********************************************************************/
void adjust_row_limits( //tidy limits
TO_BLOCK *block //block to do
) {
TO_ROW *row; //current row
float size; //size of row
float ymax; //top of row
float ymin; //bottom of row
TO_ROW_IT row_it = block->get_rows ();
if (textord_show_expanded_rows)
tprintf("Adjusting row limits for block(%d,%d)\n",
block->block->bounding_box().left(),
block->block->bounding_box().top());
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
row = row_it.data ();
size = row->max_y () - row->min_y ();
if (textord_show_expanded_rows)
tprintf("Row at %f has min %f, max %f, size %f\n",
row->intercept(), row->min_y(), row->max_y(), size);
size /= textord_merge_x + textord_merge_asc + textord_merge_desc;
ymax = size * (textord_merge_x + textord_merge_asc);
ymin = -size * textord_merge_desc;
row->set_limits (row->intercept () + ymin, row->intercept () + ymax);
row->merged = FALSE;
}
}
/**********************************************************************
* compute_row_stats
*
* Compute the linespacing and offset.
**********************************************************************/
void compute_row_stats( //find lines
TO_BLOCK *block, //block to do
BOOL8 testing_on //correct orientation
) {
inT32 row_index; //of median
TO_ROW *row; //current row
TO_ROW *prev_row; //previous row
float iqr; //inter quartile range
TO_ROW_IT row_it = block->get_rows ();
//number of rows
inT16 rowcount = row_it.length ();
TO_ROW **rows; //for choose nth
rows = (TO_ROW **) alloc_mem (rowcount * sizeof (TO_ROW *));
if (rows == NULL)
MEMORY_OUT.error ("compute_row_stats", ABORT, NULL);
rowcount = 0;
prev_row = NULL;
row_it.move_to_last (); //start at bottom
do {
row = row_it.data ();
if (prev_row != NULL) {
rows[rowcount++] = prev_row;
prev_row->spacing = row->intercept () - prev_row->intercept ();
if (testing_on)
tprintf ("Row at %g yields spacing of %g\n",
row->intercept (), prev_row->spacing);
}
prev_row = row;
row_it.backward ();
}
while (!row_it.at_last ());
block->key_row = prev_row;
block->baseline_offset =
fmod (prev_row->parallel_c (), block->line_spacing);
if (testing_on)
tprintf ("Blob based spacing=(%g,%g), offset=%g",
block->line_size, block->line_spacing, block->baseline_offset);
if (rowcount > 0) {
row_index = choose_nth_item (rowcount * 3 / 4, rows, rowcount,
sizeof (TO_ROW *), row_spacing_order);
iqr = rows[row_index]->spacing;
row_index = choose_nth_item (rowcount / 4, rows, rowcount,
sizeof (TO_ROW *), row_spacing_order);
iqr -= rows[row_index]->spacing;
row_index = choose_nth_item (rowcount / 2, rows, rowcount,
sizeof (TO_ROW *), row_spacing_order);
block->key_row = rows[row_index];
if (testing_on)
tprintf (" row based=%g(%g)", rows[row_index]->spacing, iqr);
if (rowcount > 2
&& iqr < rows[row_index]->spacing * textord_linespace_iqrlimit) {
if (!textord_new_initial_xheight) {
if (rows[row_index]->spacing < block->line_spacing
&& rows[row_index]->spacing > block->line_size)
//within range
block->line_size = rows[row_index]->spacing;
//spacing=size
else if (rows[row_index]->spacing > block->line_spacing)
block->line_size = block->line_spacing;
//too big so use max
}
else {
if (rows[row_index]->spacing < block->line_spacing)
block->line_size = rows[row_index]->spacing;
else
block->line_size = block->line_spacing;
//too big so use max
}
if (block->line_size < textord_min_xheight)
block->line_size = (float) textord_min_xheight;
block->line_spacing = rows[row_index]->spacing;
block->max_blob_size =
block->line_spacing * textord_excess_blobsize;
}
block->baseline_offset = fmod (rows[row_index]->intercept (),
block->line_spacing);
}
if (testing_on)
tprintf ("\nEstimate line size=%g, spacing=%g, offset=%g\n",
block->line_size, block->line_spacing, block->baseline_offset);
free_mem(rows);
}
/**********************************************************************
* compute_block_xheight
*
* Compute the xheight of the individual rows, then correlate them
* and interpret ascenderless lines, correcting xheights.
**********************************************************************/
void compute_block_xheight( //find lines
TO_BLOCK *block, //block to do
float gradient //global skew
) {
TO_ROW *row; //current row
int xh_count, desc_count; //no of samples
float block_median; //median blob size
int asc_count, cap_count;
inT32 min_size, max_size; //limits on xheight
inT32 evidence; //no of samples on row
float xh_sum, desc_sum; //for averages
float asc_sum, cap_sum;
TO_ROW_IT row_it = block->get_rows ();
STATS row_heights; //block evidence
if (row_it.empty ())
return; //no rows
block_median = median_block_xheight (block, gradient);
block_median *= 2;
if (block_median < block->line_size)
block_median = block->line_size;
// tprintf("Block median=%g, linesize=%g\n",
// block_median,block->line_size);
max_size = (inT32) ceil (block_median);
min_size = (inT32) floor (block_median * textord_minxh);
row_heights.set_range (min_size, max_size + 1);
xh_count = desc_count = asc_count = cap_count = 0;
xh_sum = desc_sum = asc_sum = cap_sum = 0.0f;
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
row = row_it.data ();
evidence = compute_row_xheight (row, min_size, max_size, gradient);
if (row->xheight > 0 && row->ascrise > 0) {
row_heights.add ((inT32) row->xheight, evidence);
xh_count += evidence;
asc_sum += row->ascrise;
asc_count++;
}
else if (row->xheight > 0) {
cap_sum += row->xheight; //assume just caps
cap_count++;
}
if (row->descdrop != 0) {
desc_sum += row->descdrop;
desc_count++;
}
}
if (xh_count > 0) {
//median
xh_sum = row_heights.ile (0.5);
asc_sum /= asc_count;
}
else if (cap_count > 0) {
cap_sum /= cap_count; //must assume caps
xh_sum =
cap_sum * textord_merge_x / (textord_merge_x + textord_merge_asc);
asc_sum =
cap_sum * textord_merge_asc / (textord_merge_x + textord_merge_asc);
}
else {
//default sizes
xh_sum = block_median * textord_merge_x;
asc_sum = block_median * textord_merge_asc;
}
if (desc_count > 0) {
desc_sum /= desc_count;
}
else {
desc_sum = xh_sum * textord_merge_desc / textord_merge_x;
}
// tprintf("Block average x height=%g, count=%d, asc=%g/%d, desc=%g/%d,cap=%g/%d\n",
// xh_sum,xh_count,asc_sum,asc_count,desc_sum,desc_count,
// cap_sum,cap_count);
if (xh_sum < textord_min_xheight)
xh_sum = (float) textord_min_xheight;
block->xheight = xh_sum;
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
correct_row_xheight (row_it.data (), xh_sum, asc_sum, desc_sum);
}
}
/**********************************************************************
* median_block_xheight
*
* Compute the linespacing and offset.
**********************************************************************/
float median_block_xheight( //find lines
TO_BLOCK *block, //block to do
float gradient //global skew
) {
TO_ROW *row; //current row
float result; //output size
float xcentre; //centre of blob
TO_ROW_IT row_it = block->get_rows ();
BLOBNBOX_IT blob_it;
BLOBNBOX *blob; //current blob
float *heights; //for choose nth
inT32 blob_count; //blobs in block
inT32 blob_index; //current blob
blob_count = 0;
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ())
blob_count += row_it.data ()->blob_list ()->length ();
heights = (float *) alloc_mem (blob_count * sizeof (float));
if (heights == NULL)
MEMORY_OUT.error ("compute_row_stats", ABORT, NULL);
blob_index = 0;
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
row = row_it.data ();
blob_it.set_to_list (row->blob_list ());
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
blob_it.forward ()) {
blob = blob_it.data ();
if (!blob->joined_to_prev ()) {
xcentre =
(blob->bounding_box ().left () +
blob->bounding_box ().right ()) / 2.0f;
heights[blob_index] =
blob->bounding_box ().top () - gradient * xcentre -
row->parallel_c ();
if (heights[blob_index] > 0)
blob_index++;
}
}
}
ASSERT_HOST (blob_index > 0); //dont expect 0
blob_count = blob_index;
blob_index = choose_nth_item (blob_count / 2, heights, blob_count);
result = heights[blob_index];
free_mem(heights);
return result;
}
/**********************************************************************
* compute_row_xheight
*
* Estimate the xheight of this row.
* Compute the ascender rise and descender drop at the same time.
**********************************************************************/
inT32 compute_row_xheight( //find lines
TO_ROW *row, //row to do
inT32 min_height, //min xheight
inT32 max_height, //max xheight
float gradient //global skew
) {
BOOL8 in_best_pile; //control of mode size
inT32 prev_size; //previous size
float xcentre; //centre of blob
float height; //height of blob
BLOBNBOX_IT blob_it = row->blob_list ();
BLOBNBOX *blob; //current blob
inT32 blob_count; //blobs in block
inT32 x; //xheight index
inT32 asc; //ascender index
inT32 blob_index; //current blob
inT32 mode_count; //no of modes
inT32 best_count; //count of best x so far
float ratio; //size ratio
inT32 modes[MAX_HEIGHT_MODES]; //biggest piles
STATS heights (min_height, max_height + 1);
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list (); blob_it.forward ()) {
blob = blob_it.data ();
if (!blob->joined_to_prev ()) {
xcentre =
(blob->bounding_box ().left () +
blob->bounding_box ().right ()) / 2.0f;
height = blob->bounding_box ().top ();
if (textord_fix_xheight_bug)
height -= row->baseline.y (xcentre);
else
height -= gradient * xcentre + row->parallel_c ();
if (height >= min_height && height <= max_height
&& (!textord_xheight_tweak || height > textord_min_xheight))
heights.add ((inT32) floor (height + 0.5), 1);
}
}
blob_index = heights.mode (); //find mode
//get count of mode
blob_count = heights.pile_count (blob_index);
if (textord_debug_xheights)
tprintf ("min_height=%d, max_height=%d, mode=%d, count=%d, total=%d,%d\n",
min_height, max_height, blob_index, blob_count,
heights.get_total (), row->blob_list ()->length ());
row->ascrise = 0.0f;
row->xheight = 0.0f;
row->descdrop = 0.0f; //undefined;
in_best_pile = FALSE;
prev_size = -MAX_INT32;
best_count = 0;
if (blob_count > 0) {
//get biggest ones
mode_count = compute_height_modes (&heights, min_height, max_height, modes, MAX_HEIGHT_MODES);
for (x = 0; x < mode_count - 1; x++) {
if (modes[x] != prev_size + 1)
in_best_pile = FALSE; //had empty height
if (heights.pile_count (modes[x])
>= blob_count * textord_xheight_mode_fraction
&& (in_best_pile || heights.pile_count (modes[x]) > best_count)) {
for (asc = x + 1; asc < mode_count; asc++) {
ratio = (float) modes[asc] / modes[x];
if (textord_ascx_ratio_min < ratio
&& ratio < textord_ascx_ratio_max
&& heights.pile_count (modes[asc])
>= blob_count * textord_ascheight_mode_fraction) {
if (heights.pile_count (modes[x]) > best_count) {
in_best_pile = TRUE;
best_count = heights.pile_count (modes[x]);
}
// tprintf("X=%d, asc=%d, count=%d, ratio=%g\n",
// modes[x],modes[asc]-modes[x],
// heights.pile_count(modes[x]),
// ratio);
prev_size = modes[x];
row->xheight = (float) modes[x];
row->ascrise = (float) (modes[asc] - modes[x]);
}
}
}
}
if (row->xheight == 0) {
//single mode
row->xheight = (float) blob_index;
row->ascrise = 0.0f;
if (textord_debug_xheights)
tprintf ("Single mode xheight set to %g\n", row->xheight);
}
else if (textord_debug_xheights)
tprintf ("Multi-mode xheight set to %g, asc=%g\n",
row->xheight, row->ascrise);
row->descdrop = (float) compute_row_descdrop (row, gradient);
//find descenders
}
return best_count;
}
/**********************************************************************
* compute_row_descdrop
*
* Estimate the descdrop of this row.
**********************************************************************/
inT32 compute_row_descdrop( //find lines
TO_ROW *row, //row to do
float gradient //global skew
) {
inT32 min_height = (inT32) floor (row->xheight * textord_descx_ratio_min);
inT32 max_height = (inT32) floor (row->xheight * textord_descx_ratio_max);
float xcentre; //centre of blob
float height; //height of blob
BLOBNBOX_IT blob_it = row->blob_list ();
BLOBNBOX *blob; //current blob
inT32 blob_count; //blobs in block
inT32 blob_index; //current blob
STATS heights (min_height, max_height + 1);
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list (); blob_it.forward ()) {
blob = blob_it.data ();
if (!blob->joined_to_prev ()) {
xcentre =
(blob->bounding_box ().left () +
blob->bounding_box ().right ()) / 2.0f;
height =
gradient * xcentre + row->parallel_c () -
blob->bounding_box ().bottom ();
if (height >= min_height && height <= max_height)
heights.add ((inT32) floor (height + 0.5), 1);
}
}
blob_index = heights.mode (); //find mode
//get count of mode
blob_count = heights.pile_count (blob_index);
return blob_count > 0 ? -blob_index : 0;
}
/**********************************************************************
* compute_height_modes
*
* Find the top maxmodes values in the input array and put their
* indices in the output in the order in which they occurred.
**********************************************************************/
inT32 compute_height_modes( //find lines
STATS *heights, //stats to search
inT32 min_height, //bottom of range
inT32 max_height, //top of range
inT32 *modes, //output array
inT32 maxmodes //size of modes
) {
inT32 pile_count; //no in source pile
inT32 src_count; //no of source entries
inT32 src_index; //current entry
inT32 least_count; //height of smalllest
inT32 least_index; //index of least
inT32 dest_count; //index in modes
src_count = max_height + 1 - min_height;
dest_count = 0;
least_count = MAX_INT32;
least_index = -1;
for (src_index = 0; src_index < src_count; src_index++) {
pile_count = heights->pile_count (min_height + src_index);
if (pile_count > 0) {
if (dest_count < maxmodes) {
if (pile_count < least_count) {
//find smallest in array
least_count = pile_count;
least_index = dest_count;
}
modes[dest_count++] = min_height + src_index;
}
else if (pile_count >= least_count) {
while (least_index < maxmodes - 1) {
modes[least_index] = modes[least_index + 1];
//shuffle up
least_index++;
}
//new one on end
modes[maxmodes - 1] = min_height + src_index;
if (pile_count == least_count) {
//new smallest
least_index = maxmodes - 1;
}
else {
least_count = heights->pile_count (modes[0]);
least_index = 0;
for (dest_count = 1; dest_count < maxmodes; dest_count++) {
pile_count = heights->pile_count (modes[dest_count]);
if (pile_count < least_count) {
//find smallest
least_count = pile_count;
least_index = dest_count;
}
}
}
}
}
}
return dest_count;
}
/**********************************************************************
* correct_row_xheight
*
* Adjust the xheight etc of this row if not within reasonable limits
* of the average for the block.
**********************************************************************/
void correct_row_xheight( //fix bad values
TO_ROW *row, //row to fix
float xheight, //average values
float ascrise,
float descdrop) {
if (textord_row_xheights) {
if (row->xheight <= 0)
row->xheight = xheight;
if (row->ascrise < row->xheight * (textord_ascx_ratio_min - 1)) {
if (row->xheight >= xheight * (1 - textord_xheight_error_margin)
&& row->xheight <= xheight * (1 + textord_xheight_error_margin)) {
row->all_caps = FALSE;
row->ascrise = ascrise;
}
else if (row->xheight >=
(xheight + ascrise) * (1 - textord_xheight_error_margin)
&& row->xheight <=
(xheight + ascrise) * (1 + textord_xheight_error_margin)) {
row->all_caps = TRUE;
//it was caps
row->ascrise = row->xheight - xheight;
row->xheight = xheight;
}
else {
row->all_caps = TRUE;
row->ascrise = row->xheight * ascrise / (xheight + ascrise);
row->xheight -= row->ascrise;
}
}
else
row->all_caps = FALSE;
row->ascrise = ascrise;
if (row->descdrop >= -row->xheight * (textord_ascx_ratio_min - 1))
row->descdrop = descdrop;
}
else {
if (row->xheight < xheight * (1 - textord_xheight_error_margin)
|| row->xheight > xheight * (1 + textord_xheight_error_margin))
row->xheight = xheight; //set to average
row->all_caps = row->ascrise <= 0;
if (row->ascrise < ascrise * (1 - textord_xheight_error_margin)
|| row->ascrise > ascrise * (1 + textord_xheight_error_margin))
row->ascrise = ascrise; //set to average
if (row->descdrop < descdrop * (1 - textord_xheight_error_margin)
|| row->descdrop > descdrop * (1 + textord_xheight_error_margin))
row->descdrop = descdrop; //set to average
}
}
/**********************************************************************
* separate_underlines
*
* Test wide objects for being potential underlines. If they are then
* put them in a separate list in the block.
**********************************************************************/
void separate_underlines( //make rough chars
TO_BLOCK *block, //block to do
float gradient, //skew angle
FCOORD rotation, //inverse landscape
BOOL8 testing_on //correct orientation
) {
BLOBNBOX *blob; //current blob
PBLOB *poly_blob; //rotated blob
C_BLOB *rotated_blob; //rotated blob
TO_ROW *row; //current row
float length; //of g_vec
TBOX blob_box;
FCOORD blob_rotation; //inverse of rotation
FCOORD g_vec; //skew rotation
BLOBNBOX_IT blob_it; //iterator
//iterator
BLOBNBOX_IT under_it = &block->underlines;
TO_ROW_IT row_it = block->get_rows ();
//length of vector
length = sqrt (1 + gradient * gradient);
g_vec = FCOORD (1 / length, -gradient / length);
blob_rotation = FCOORD (rotation.x (), -rotation.y ());
blob_rotation.rotate (g_vec); //unoding everything
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
row = row_it.data ();
//get blobs
blob_it.set_to_list (row->blob_list ());
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
blob_it.forward ()) {
blob = blob_it.data ();
blob_box = blob->bounding_box ();
if (blob_box.width () > block->line_size * textord_underline_width) {
if (textord_cblob_blockocc && blob->cblob () != NULL) {
rotated_blob = crotate_cblob (blob->cblob (),
blob_rotation);
if (test_underline (testing_on && textord_show_final_rows,
rotated_blob, (inT16) row->intercept (),
(inT16) (block->line_size *
(textord_merge_x +
textord_merge_asc / 2.0f)))) {
under_it.add_after_then_move (blob_it.extract ());
if (testing_on && textord_show_final_rows) {
tprintf ("Underlined blob at (%d,%d)->(%d,%d) ",
rotated_blob->bounding_box ().left (),
rotated_blob->bounding_box ().bottom (),
rotated_blob->bounding_box ().right (),
rotated_blob->bounding_box ().top ());
tprintf ("(Was (%d,%d)->(%d,%d))\n",
blob_box.left (), blob_box.bottom (),
blob_box.right (), blob_box.top ());
}
}
delete rotated_blob;
}
else {
if (blob->blob () != NULL) {
// if (testing_on && textord_show_final_rows)
// tprintf("Rotating by (%g,%g)\n",
// blob_rotation.x(),blob_rotation.y());
poly_blob = rotate_blob (blob->blob (), blob_rotation);
}
else
poly_blob = rotate_cblob (blob->cblob (),
block->line_size,
blob_rotation);
if (test_underline
(testing_on
&& textord_show_final_rows, poly_blob,
row->intercept (),
block->line_size * (textord_merge_x +
textord_merge_asc / 2))) {
if (testing_on && textord_show_final_rows) {
tprintf ("Underlined blob at (%d,%d)->(%d,%d) ",
poly_blob->bounding_box ().left (),
poly_blob->bounding_box ().bottom (),
poly_blob->bounding_box ().right (),
poly_blob->bounding_box ().top ());
tprintf ("(Was (%d,%d)->(%d,%d))\n",
blob_box.left (), blob_box.bottom (),
blob_box.right (), blob_box.top ());
}
under_it.add_after_then_move (blob_it.extract ());
}
delete poly_blob;
}
}
}
}
}
/**********************************************************************
* pre_associate_blobs
*
* Associate overlapping blobs and fake chop wide blobs.
**********************************************************************/
void pre_associate_blobs( //make rough chars
ICOORD page_tr, //top right
TO_BLOCK *block, //block to do
FCOORD rotation, //inverse landscape
BOOL8 testing_on //correct orientation
) {
#ifndef GRAPHICS_DISABLED
ScrollView::Color colour; //of boxes
#endif
BLOBNBOX *blob; //current blob
BLOBNBOX *nextblob; //next in list
TBOX blob_box;
FCOORD blob_rotation; //inverse of rotation
BLOBNBOX_IT blob_it; //iterator
BLOBNBOX_IT start_it; //iterator
TO_ROW_IT row_it = block->get_rows ();
#ifndef GRAPHICS_DISABLED
colour = ScrollView::RED;
#endif
blob_rotation = FCOORD (rotation.x (), -rotation.y ());
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
//get blobs
blob_it.set_to_list (row_it.data ()->blob_list ());
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
blob_it.forward ()) {
blob = blob_it.data ();
blob_box = blob->bounding_box ();
start_it = blob_it; //save start point
// if (testing_on && textord_show_final_blobs)
// {
// tprintf("Blob at (%d,%d)->(%d,%d), addr=%x, count=%d\n",
// blob_box.left(),blob_box.bottom(),
// blob_box.right(),blob_box.top(),
// (void*)blob,blob_it.length());
// }
bool overlap;
do {
overlap = false;
if (!blob_it.at_last ()) {
nextblob = blob_it.data_relative(1);
overlap = blob_box.major_x_overlap(nextblob->bounding_box());
if (overlap) {
blob->merge(nextblob); // merge new blob
blob_box = blob->bounding_box(); // get bigger box
blob_it.forward();
}
}
}
while (overlap);
blob->chop (&start_it, &blob_it,
blob_rotation,
block->line_size * textord_merge_x *
textord_chop_width);
//attempt chop
}
#ifndef GRAPHICS_DISABLED
if (testing_on && textord_show_final_blobs) {
if (to_win == NULL)
create_to_win(page_tr);
to_win->Pen(colour);
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
blob_it.forward ()) {
blob = blob_it.data ();
blob_box = blob->bounding_box ();
blob_box.rotate (rotation);
if (!blob->joined_to_prev ()) {
to_win->Rectangle (blob_box.left (), blob_box.bottom (),
blob_box.right (), blob_box.top ());
}
}
colour = (ScrollView::Color) (colour + 1);
if (colour > ScrollView::MAGENTA)
colour = ScrollView::RED;
}
#endif
}
}
/**********************************************************************
* fit_parallel_rows
*
* Re-fit the rows in the block to the given gradient.
**********************************************************************/
void fit_parallel_rows( //find lines
TO_BLOCK *block, //block to do
float gradient, //gradient to fit
FCOORD rotation, //for drawing
inT32 block_edge, //edge of block
BOOL8 testing_on //correct orientation
) {
#ifndef GRAPHICS_DISABLED
ScrollView::Color colour; //of row
#endif
TO_ROW_IT row_it = block->get_rows ();
row_it.move_to_first ();
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
if (row_it.data ()->blob_list ()->empty ())
delete row_it.extract (); //nothing in it
else
fit_parallel_lms (gradient, row_it.data ());
}
#ifndef GRAPHICS_DISABLED
if (testing_on) {
colour = ScrollView::RED;
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
plot_parallel_row (row_it.data (), gradient,
block_edge, colour, rotation);
colour = (ScrollView::Color) (colour + 1);
if (colour > ScrollView::MAGENTA)
colour = ScrollView::RED;
}
}
#endif
row_it.sort (row_y_order); //may have gone out of order
}
/**********************************************************************
* fit_parallel_lms
*
* Fit an LMS line to a row.
* Make the fit parallel to the given gradient and set the
* row accordingly.
**********************************************************************/
void fit_parallel_lms( //sort function
float gradient, //forced gradient
TO_ROW *row //row to fit
) {
float c; //fitted line
int blobcount; //no of blobs
TBOX box; //blob box
LMS lms (row->blob_list ()->length ());
//blobs
BLOBNBOX_IT blob_it = row->blob_list ();
blobcount = 0;
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list (); blob_it.forward ()) {
if (!blob_it.data ()->joined_to_prev ()) {
box = blob_it.data ()->bounding_box ();
lms.
add (FCOORD ((box.left () + box.right ()) / 2.0, box.bottom ()));
blobcount++;
}
}
lms.constrained_fit (gradient, c);
row->set_parallel_line (gradient, c, lms.error ());
if (textord_straight_baselines && blobcount > lms_line_trials) {
lms.fit (gradient, c);
}
//set the other too
row->set_line (gradient, c, lms.error ());
}
/**********************************************************************
* make_spline_rows
*
* Re-fit the rows in the block to the given gradient.
**********************************************************************/
void make_spline_rows( //find lines
TO_BLOCK *block, //block to do
float gradient, //gradient to fit
FCOORD rotation, //for drawing
inT32 block_edge, //edge of block
BOOL8 testing_on //correct orientation
) {
#ifndef GRAPHICS_DISABLED
ScrollView::Color colour; //of row
#endif
TO_ROW_IT row_it = block->get_rows ();
row_it.move_to_first ();
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
if (row_it.data ()->blob_list ()->empty ())
delete row_it.extract (); //nothing in it
else
make_baseline_spline (row_it.data (), block);
}
if (textord_old_baselines) {
#ifndef GRAPHICS_DISABLED
if (testing_on) {
colour = ScrollView::RED;
for (row_it.mark_cycle_pt (); !row_it.cycled_list ();
row_it.forward ()) {
row_it.data ()->baseline.plot (to_win, colour);
colour = (ScrollView::Color) (colour + 1);
if (colour > ScrollView::MAGENTA)
colour = ScrollView::RED;
}
}
#endif
make_old_baselines(block, testing_on);
}
#ifndef GRAPHICS_DISABLED
if (testing_on) {
colour = ScrollView::RED;
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
row_it.data ()->baseline.plot (to_win, colour);
colour = (ScrollView::Color) (colour + 1);
if (colour > ScrollView::MAGENTA)
colour = ScrollView::RED;
}
}
#endif
}
/**********************************************************************
* make_baseline_spline
*
* Fit an LMS line to a row.
* Make the fit parallel to the given gradient and set the
* row accordingly.
**********************************************************************/
void make_baseline_spline( //sort function
TO_ROW *row, //row to fit
TO_BLOCK *block //block it came from
) {
float b, c; //fitted curve
float middle; //x middle of blob
TBOX box; //blob box
LMS lms (row->blob_list ()->length ());
//blobs
BLOBNBOX_IT blob_it = row->blob_list ();
inT32 *xstarts; //spline boundaries
double *coeffs; //quadratic coeffs
inT32 segments; //no of segments
inT32 segment; //current segment
xstarts =
(inT32 *) alloc_mem ((row->blob_list ()->length () + 1) * sizeof (inT32));
if (segment_baseline (row, block, segments, xstarts)
&& !textord_straight_baselines && !textord_parallel_baselines) {
if (textord_quadratic_baselines) {
coeffs = (double *) alloc_mem (segments * 3 * sizeof (double));
for (segment = 0; segment < segments; segment++) {
lms.clear ();
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
blob_it.forward ()) {
if (!blob_it.data ()->joined_to_prev ()) {
box = blob_it.data ()->bounding_box ();
middle = (box.left () + box.right ()) / 2.0;
if (middle >= xstarts[segment]
&& middle < xstarts[segment + 1]) {
lms.add (FCOORD (middle, box.bottom ()));
}
}
}
if (textord_quadratic_baselines)
lms.fit_quadratic (block->line_size *
textord_spline_outlier_fraction,
coeffs[segment * 3], b, c);
else {
lms.fit (b, c);
coeffs[segment * 3] = 0;
}
coeffs[segment * 3 + 1] = b;
coeffs[segment * 3 + 2] = c;
}
}
else
coeffs = linear_spline_baseline (row, block, segments, xstarts);
}
else {
xstarts[1] = xstarts[segments];
segments = 1;
coeffs = (double *) alloc_mem (3 * sizeof (double));
coeffs[0] = 0;
coeffs[1] = row->line_m ();
coeffs[2] = row->line_c ();
}
row->baseline = QSPLINE (segments, xstarts, coeffs);
free_mem(coeffs);
free_mem(xstarts);
}
/**********************************************************************
* segment_baseline
*
* Divide the baseline up into segments which require a different
* quadratic fitted to them.
* Return TRUE if enough blobs were far enough away to need a quadratic.
**********************************************************************/
BOOL8
segment_baseline ( //split baseline
TO_ROW * row, //row to fit
TO_BLOCK * block, //block it came from
inT32 & segments, //no fo segments
inT32 xstarts[] //coords of segments
) {
BOOL8 needs_curve; //needs curved line
int blobcount; //no of blobs
int blobindex; //current blob
int last_state; //above, on , below
int state; //of current blob
float yshift; //from baseline
TBOX box; //blob box
TBOX new_box; //new_it box
float middle; //xcentre of blob
//blobs
BLOBNBOX_IT blob_it = row->blob_list ();
BLOBNBOX_IT new_it = blob_it; //front end
SORTED_FLOATS yshifts; //shifts from baseline
needs_curve = FALSE;
box = box_next_pre_chopped (&blob_it);
xstarts[0] = box.left ();
segments = 1;
blobcount = row->blob_list ()->length ();
if (textord_oldbl_debug)
tprintf ("Segmenting baseline of %d blobs at (%d,%d)\n",
blobcount, box.left (), box.bottom ());
if (blobcount <= textord_spline_medianwin
|| blobcount < textord_spline_minblobs) {
blob_it.move_to_last ();
box = blob_it.data ()->bounding_box ();
xstarts[1] = box.right ();
return FALSE;
}
last_state = 0;
new_it.mark_cycle_pt ();
for (blobindex = 0; blobindex < textord_spline_medianwin; blobindex++) {
new_box = box_next_pre_chopped (&new_it);
middle = (new_box.left () + new_box.right ()) / 2.0;
yshift = new_box.bottom () - row->line_m () * middle - row->line_c ();
//record shift
yshifts.add (yshift, blobindex);
if (new_it.cycled_list ()) {
xstarts[1] = new_box.right ();
return FALSE;
}
}
for (blobcount = 0; blobcount < textord_spline_medianwin / 2; blobcount++)
box = box_next_pre_chopped (&blob_it);
do {
new_box = box_next_pre_chopped (&new_it);
//get middle one
yshift = yshifts[textord_spline_medianwin / 2];
if (yshift > textord_spline_shift_fraction * block->line_size)
state = 1;
else if (-yshift > textord_spline_shift_fraction * block->line_size)
state = -1;
else
state = 0;
if (state != 0)
needs_curve = TRUE;
// tprintf("State=%d, prev=%d, shift=%g\n",
// state,last_state,yshift);
if (state != last_state && blobcount > textord_spline_minblobs) {
xstarts[segments++] = box.left ();
blobcount = 0;
}
last_state = state;
yshifts.remove (blobindex - textord_spline_medianwin);
box = box_next_pre_chopped (&blob_it);
middle = (new_box.left () + new_box.right ()) / 2.0;
yshift = new_box.bottom () - row->line_m () * middle - row->line_c ();
yshifts.add (yshift, blobindex);
blobindex++;
blobcount++;
}
while (!new_it.cycled_list ());
if (blobcount > textord_spline_minblobs || segments == 1) {
xstarts[segments] = new_box.right ();
}
else {
xstarts[--segments] = new_box.right ();
}
if (textord_oldbl_debug)
tprintf ("Made %d segments on row at (%d,%d)\n",
segments, box.right (), box.bottom ());
return needs_curve;
}
/**********************************************************************
* linear_spline_baseline
*
* Divide the baseline up into segments which require a different
* quadratic fitted to them.
* Return TRUE if enough blobs were far enough away to need a quadratic.
**********************************************************************/
double *
linear_spline_baseline ( //split baseline
TO_ROW * row, //row to fit
TO_BLOCK * block, //block it came from
inT32 & segments, //no fo segments
inT32 xstarts[] //coords of segments
) {
int blobcount; //no of blobs
int blobindex; //current blob
int index1, index2; //blob numbers
int blobs_per_segment; //blobs in each
TBOX box; //blob box
TBOX new_box; //new_it box
float middle; //xcentre of blob
//blobs
BLOBNBOX_IT blob_it = row->blob_list ();
BLOBNBOX_IT new_it = blob_it; //front end
float b, c; //fitted curve
LMS lms (row->blob_list ()->length ());
double *coeffs; //quadratic coeffs
inT32 segment; //current segment
box = box_next_pre_chopped (&blob_it);
xstarts[0] = box.left ();
blobcount = 1;
while (!blob_it.at_first ()) {
blobcount++;
box = box_next_pre_chopped (&blob_it);
}
segments = blobcount / textord_spline_medianwin;
if (segments < 1)
segments = 1;
blobs_per_segment = blobcount / segments;
coeffs = (double *) alloc_mem (segments * 3 * sizeof (double));
if (textord_oldbl_debug)
tprintf
("Linear splining baseline of %d blobs at (%d,%d), into %d segments of %d blobs\n",
blobcount, box.left (), box.bottom (), segments, blobs_per_segment);
segment = 1;
for (index2 = 0; index2 < blobs_per_segment / 2; index2++)
box_next_pre_chopped(&new_it);
index1 = 0;
blobindex = index2;
do {
blobindex += blobs_per_segment;
lms.clear ();
while (index1 < blobindex || (segment == segments && index1 < blobcount)) {
box = box_next_pre_chopped (&blob_it);
middle = (box.left () + box.right ()) / 2.0;
lms.add (FCOORD (middle, box.bottom ()));
index1++;
if (index1 == blobindex - blobs_per_segment / 2
|| index1 == blobcount - 1) {
xstarts[segment] = box.left ();
}
}
lms.fit (b, c);
coeffs[segment * 3 - 3] = 0;
coeffs[segment * 3 - 2] = b;
coeffs[segment * 3 - 1] = c;
segment++;
if (segment > segments)
break;
blobindex += blobs_per_segment;
lms.clear ();
while (index2 < blobindex || (segment == segments && index2 < blobcount)) {
new_box = box_next_pre_chopped (&new_it);
middle = (new_box.left () + new_box.right ()) / 2.0;
lms.add (FCOORD (middle, new_box.bottom ()));
index2++;
if (index2 == blobindex - blobs_per_segment / 2
|| index2 == blobcount - 1) {
xstarts[segment] = new_box.left ();
}
}
lms.fit (b, c);
coeffs[segment * 3 - 3] = 0;
coeffs[segment * 3 - 2] = b;
coeffs[segment * 3 - 1] = c;
segment++;
}
while (segment <= segments);
return coeffs;
}
/**********************************************************************
* assign_blobs_to_rows
*
* Make enough rows to allocate all the given blobs to one.
* If a block skew is given, use that, else attempt to track it.
**********************************************************************/
void assign_blobs_to_rows( //find lines
TO_BLOCK *block, //block to do
float *gradient, //block skew
int pass, //identification
BOOL8 reject_misses, //chuck big ones out
BOOL8 make_new_rows, //add rows for unmatched
BOOL8 drawing_skew //draw smoothed skew
) {
OVERLAP_STATE overlap_result; //what to do with it
float ycoord; //current y
float top, bottom; //of blob
float g_length = 1.0f; //from gradient
inT16 row_count; //no of rows
inT16 left_x; //left edge
inT16 last_x; //previous edge
float block_skew; //y delta
float smooth_factor; //for new coords
float near_dist; //dist to nearest row
ICOORD testpt; //testing only
BLOBNBOX *blob; //current blob
TO_ROW *row; //current row
TO_ROW *dest_row; //row to put blob in
//iterators
BLOBNBOX_IT blob_it = &block->blobs;
TO_ROW_IT row_it = block->get_rows ();
ycoord =
(block->block->bounding_box ().bottom () +
block->block->bounding_box ().top ()) / 2.0f;
if (gradient != NULL)
g_length = sqrt (1 + *gradient * *gradient);
#ifndef GRAPHICS_DISABLED
if (drawing_skew)
to_win->SetCursor(block->block->bounding_box ().left (), ycoord);
#endif
testpt = ICOORD (textord_test_x, textord_test_y);
blob_it.sort (blob_x_order);
smooth_factor = 1.0;
block_skew = 0.0f;
row_count = row_it.length (); //might have rows
if (!blob_it.empty ()) {
left_x = blob_it.data ()->bounding_box ().left ();
}
else {
left_x = block->block->bounding_box ().left ();
}
last_x = left_x;
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list (); blob_it.forward ()) {
blob = blob_it.data ();
if (gradient != NULL) {
block_skew = (1 - 1 / g_length) * blob->bounding_box ().bottom ()
+ *gradient / g_length * blob->bounding_box ().left ();
}
else if (blob->bounding_box ().left () - last_x > block->line_size / 2
&& last_x - left_x > block->line_size * 2
&& textord_interpolating_skew) {
// tprintf("Interpolating skew from %g",block_skew);
block_skew *= (float) (blob->bounding_box ().left () - left_x)
/ (last_x - left_x);
// tprintf("to %g\n",block_skew);
}
last_x = blob->bounding_box ().left ();
top = blob->bounding_box ().top () - block_skew;
bottom = blob->bounding_box ().bottom () - block_skew;
#ifndef GRAPHICS_DISABLED
if (drawing_skew)
to_win->DrawTo(blob->bounding_box ().left (), ycoord + block_skew);
#endif
if (!row_it.empty ()) {
for (row_it.move_to_first ();
!row_it.at_last () && row_it.data ()->min_y () > top;
row_it.forward ());
row = row_it.data ();
if (row->min_y () <= top && row->max_y () >= bottom) {
//any overlap
dest_row = row;
overlap_result = most_overlapping_row (&row_it, dest_row,
top, bottom,
block->line_size,
blob->bounding_box ().
contains (testpt));
if (overlap_result == NEW_ROW && !reject_misses)
overlap_result = ASSIGN;
}
else {
overlap_result = NEW_ROW;
if (!make_new_rows) {
near_dist = row_it.data_relative (-1)->min_y () - top;
//below bottom
if (bottom < row->min_y ()) {
if (row->min_y () - bottom <=
(block->line_spacing -
block->line_size) * textord_merge_desc) {
//done it
overlap_result = ASSIGN;
dest_row = row;
}
}
else if (near_dist > 0
&& near_dist < bottom - row->max_y ()) {
row_it.backward ();
dest_row = row_it.data ();
if (dest_row->min_y () - bottom <=
(block->line_spacing -
block->line_size) * textord_merge_desc) {
//done it
overlap_result = ASSIGN;
}
}
else {
if (top - row->max_y () <=
(block->line_spacing -
block->line_size) * (textord_overlap_x +
textord_merge_asc)) {
//done it
overlap_result = ASSIGN;
dest_row = row;
}
}
}
}
if (overlap_result == ASSIGN)
dest_row->add_blob (blob_it.extract (), top, bottom,
block->line_size);
if (overlap_result == NEW_ROW) {
if (make_new_rows && top - bottom < block->max_blob_size) {
dest_row =
new TO_ROW (blob_it.extract (), top, bottom,
block->line_size);
row_count++;
if (bottom > row_it.data ()->min_y ())
row_it.add_before_then_move (dest_row);
//insert in right place
else
row_it.add_after_then_move (dest_row);
smooth_factor =
1.0 / (row_count * textord_skew_lag +
textord_skewsmooth_offset);
}
else
overlap_result = REJECT;
}
}
else if (make_new_rows && top - bottom < block->max_blob_size) {
overlap_result = NEW_ROW;
dest_row =
new TO_ROW (blob_it.extract (), top, bottom, block->line_size);
row_count++;
row_it.add_after_then_move (dest_row);
smooth_factor = 1.0 / (row_count * textord_skew_lag +
textord_skewsmooth_offset2);
}
else
overlap_result = REJECT;
if (blob->bounding_box ().contains (testpt)) {
if (overlap_result != REJECT) {
tprintf ("Test blob assigned to row at (%g,%g) on pass %d\n",
dest_row->min_y (), dest_row->max_y (), pass);
}
else {
tprintf ("Test blob assigned to no row on pass %d\n", pass);
}
}
if (overlap_result != REJECT) {
while (!row_it.at_first ()
&& row_it.data ()->min_y () >
row_it.data_relative (-1)->min_y ()) {
row = row_it.extract ();
row_it.backward ();
row_it.add_before_then_move (row);
}
while (!row_it.at_last ()
&& row_it.data ()->min_y () <
row_it.data_relative (1)->min_y ()) {
row = row_it.extract ();
row_it.forward ();
//keep rows in order
row_it.add_after_then_move (row);
}
block_skew = (1 - smooth_factor) * block_skew
+ smooth_factor * (blob->bounding_box ().bottom () -
dest_row->initial_min_y ());
}
}
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
if (row_it.data ()->blob_list ()->empty ())
delete row_it.extract (); //discard empty rows
}
}
/**********************************************************************
* most_overlapping_row
*
* Return the row which most overlaps the blob.
**********************************************************************/
OVERLAP_STATE most_overlapping_row( //find best row
TO_ROW_IT *row_it, //iterator
TO_ROW *&best_row, //output row
float top, //top of blob
float bottom, //bottom of blob
float rowsize, //max row size
BOOL8 testing_blob //test stuff
) {
OVERLAP_STATE result; //result of tests
float overlap; //of blob & row
float bestover; //nearest row
float merge_top, merge_bottom; //size of merged row
ICOORD testpt; //testing only
TO_ROW *row; //current row
TO_ROW *test_row; //for multiple overlaps
BLOBNBOX_IT blob_it; //for merging rows
result = ASSIGN;
row = row_it->data ();
bestover = top - bottom;
if (top > row->max_y ())
bestover -= top - row->max_y ();
if (bottom < row->min_y ())
//compute overlap
bestover -= row->min_y () - bottom;
if (testing_blob) {
tprintf ("Test blob y=(%g,%g), row=(%f,%f), overlap=%f\n",
bottom, top, row->min_y (), row->max_y (), bestover);
}
test_row = row;
do {
if (!row_it->at_last ()) {
row_it->forward ();
test_row = row_it->data ();
if (test_row->min_y () <= top && test_row->max_y () >= bottom) {
merge_top =
test_row->max_y () >
row->max_y ()? test_row->max_y () : row->max_y ();
merge_bottom =
test_row->min_y () <
row->min_y ()? test_row->min_y () : row->min_y ();
if (merge_top - merge_bottom <= rowsize) {
if (testing_blob) {
tprintf ("Merging rows at (%g,%g), (%g,%g)\n",
row->min_y (), row->max_y (),
test_row->min_y (), test_row->max_y ());
}
test_row->set_limits (merge_bottom, merge_top);
blob_it.set_to_list (test_row->blob_list ());
blob_it.add_list_after (row->blob_list ());
blob_it.sort (blob_x_order);
row_it->backward ();
delete row_it->extract ();
row_it->forward ();
bestover = -1.0f; //force replacement
}
overlap = top - bottom;
if (top > test_row->max_y ())
overlap -= top - test_row->max_y ();
if (bottom < test_row->min_y ())
overlap -= test_row->min_y () - bottom;
if (bestover >= rowsize - 1 && overlap >= rowsize - 1) {
result = REJECT;
}
if (overlap > bestover) {
bestover = overlap; //find biggest overlap
row = test_row;
}
if (testing_blob) {
tprintf
("Test blob y=(%g,%g), row=(%f,%f), overlap=%f->%f\n",
bottom, top, test_row->min_y (), test_row->max_y (),
overlap, bestover);
}
}
}
}
while (!row_it->at_last ()
&& test_row->min_y () <= top && test_row->max_y () >= bottom);
while (row_it->data () != row)
row_it->backward (); //make it point to row
//doesn't overlap much
if (top - bottom - bestover > rowsize * textord_overlap_x &&
(!textord_fix_makerow_bug || bestover < rowsize * textord_overlap_x)
&& result == ASSIGN)
result = NEW_ROW; //doesn't overlap enough
best_row = row;
return result;
}
/**********************************************************************
* blob_x_order
*
* Sort function to sort blobs in x from page left.
**********************************************************************/
int blob_x_order( //sort function
const void *item1, //items to compare
const void *item2) {
//converted ptr
BLOBNBOX *blob1 = *(BLOBNBOX **) item1;
//converted ptr
BLOBNBOX *blob2 = *(BLOBNBOX **) item2;
if (blob1->bounding_box ().left () < blob2->bounding_box ().left ())
return -1;
else if (blob1->bounding_box ().left () > blob2->bounding_box ().left ())
return 1;
else
return 0;
}
/**********************************************************************
* row_y_order
*
* Sort function to sort rows in y from page top.
**********************************************************************/
int row_y_order( //sort function
const void *item1, //items to compare
const void *item2) {
//converted ptr
TO_ROW *row1 = *(TO_ROW **) item1;
//converted ptr
TO_ROW *row2 = *(TO_ROW **) item2;
if (row1->parallel_c () > row2->parallel_c ())
return -1;
else if (row1->parallel_c () < row2->parallel_c ())
return 1;
else
return 0;
}
/**********************************************************************
* row_spacing_order
*
* Qsort style function to compare 2 TO_ROWS based on their spacing value.
**********************************************************************/
int row_spacing_order( //sort function
const void *item1, //items to compare
const void *item2) {
//converted ptr
TO_ROW *row1 = *(TO_ROW **) item1;
//converted ptr
TO_ROW *row2 = *(TO_ROW **) item2;
if (row1->spacing < row2->spacing)
return -1;
else if (row1->spacing > row2->spacing)
return 1;
else
return 0;
}