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/**********************************************************************
* File: pitsync1.cpp (Formerly pitsync.c)
* Description: Code to find the optimum fixed pitch segmentation of some blobs.
* Author: Ray Smith
*
* (C) Copyright 1992, Hewlett-Packard Ltd.
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
** http://www.apache.org/licenses/LICENSE-2.0
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*
**********************************************************************/
#include "pitsync1.h"
#include <cfloat> // for FLT_MAX
#include <cmath>
namespace tesseract {
ELISTIZE (FPSEGPT) CLISTIZE (FPSEGPT_LIST)
INT_VAR(pitsync_linear_version, 6, "Use new fast algorithm");
double_VAR(pitsync_joined_edge, 0.75, "Dist inside big blob for chopping");
double_VAR(pitsync_offset_freecut_fraction, 0.25,
"Fraction of cut for free cuts");
INT_VAR(pitsync_fake_depth, 1, "Max advance fake generation");
/**********************************************************************
* FPSEGPT::FPSEGPT
*
* Constructor to make a new FPSEGPT.
* The existing FPCUTPT is duplicated.
**********************************************************************/
FPSEGPT::FPSEGPT( //constructor
FPCUTPT *cutpt //create from new form
) {
pred = nullptr;
mean_sum = cutpt->sum ();
sq_sum = cutpt->squares ();
cost = cutpt->cost_function ();
faked = cutpt->faked;
terminal = cutpt->terminal;
fake_count = cutpt->fake_count;
xpos = cutpt->position ();
mid_cuts = cutpt->cheap_cuts ();
}
/**********************************************************************
* FPSEGPT::FPSEGPT
*
* Constructor to make a new FPSEGPT.
**********************************************************************/
FPSEGPT::FPSEGPT ( //constructor
int16_t x //position
):xpos (x) {
pred = nullptr;
mean_sum = 0;
sq_sum = 0;
cost = 0;
faked = false;
terminal = false;
fake_count = 0;
mid_cuts = 0;
}
/**********************************************************************
* FPSEGPT::FPSEGPT
*
* Constructor to make a new FPSEGPT.
**********************************************************************/
FPSEGPT::FPSEGPT ( //constructor
int16_t x, //position
bool faking, //faking this one
int16_t offset, //dist to gap
int16_t region_index, //segment number
int16_t pitch, //proposed pitch
int16_t pitch_error, //allowed tolerance
FPSEGPT_LIST * prev_list //previous segment
)
: fake_count(0),
xpos(x),
mean_sum(0.0),
sq_sum(0.0)
{
int16_t best_fake; //on previous
FPSEGPT *segpt; //segment point
int32_t dist; //from prev segment
double sq_dist; //squared distance
double mean; //mean pitch
double total; //total dists
double factor; //cost function
FPSEGPT_IT pred_it = prev_list;//for previuos segment
cost = FLT_MAX;
pred = nullptr;
faked = faking;
terminal = false;
best_fake = INT16_MAX;
mid_cuts = 0;
for (pred_it.mark_cycle_pt (); !pred_it.cycled_list (); pred_it.forward ()) {
segpt = pred_it.data ();
if (segpt->fake_count < best_fake)
best_fake = segpt->fake_count;
dist = x - segpt->xpos;
if (dist >= pitch - pitch_error && dist <= pitch + pitch_error
&& !segpt->terminal) {
total = segpt->mean_sum + dist;
sq_dist = dist * dist + segpt->sq_sum + offset * offset;
//sum of squarees
mean = total / region_index;
factor = mean - pitch;
factor *= factor;
factor += sq_dist / (region_index) - mean * mean;
if (factor < cost) {
cost = factor; //find least cost
pred = segpt; //save path
mean_sum = total;
sq_sum = sq_dist;
fake_count = segpt->fake_count + faked;
}
}
}
if (fake_count > best_fake + 1)
pred = nullptr; //fail it
}
/**********************************************************************
* check_pitch_sync
*
* Construct the lattice of possible segmentation points and choose the
* optimal path. Return the optimal path only.
* The return value is a measure of goodness of the sync.
**********************************************************************/
double check_pitch_sync( //find segmentation
BLOBNBOX_IT *blob_it, //blobs to do
int16_t blob_count, //no of blobs
int16_t pitch, //pitch estimate
int16_t pitch_error, //tolerance
STATS *projection, //vertical
FPSEGPT_LIST *seg_list //output list
) {
int16_t x; //current coord
int16_t min_index; //blob number
int16_t max_index; //blob number
int16_t left_edge; //of word
int16_t right_edge; //of word
int16_t right_max; //max allowed x
int16_t min_x; //in this region
int16_t max_x;
int16_t region_index;
int16_t best_region_index = 0; //for best result
int16_t offset; //dist to legal area
int16_t left_best_x; //edge of good region
int16_t right_best_x; //right edge
TBOX min_box; //bounding box
TBOX max_box; //bounding box
TBOX next_box; //box of next blob
FPSEGPT *segpt; //segment point
FPSEGPT_LIST *segpts; //points in a segment
double best_cost; //best path
double mean_sum; //computes result
FPSEGPT *best_end; //end of best path
BLOBNBOX_IT min_it; //copy iterator
BLOBNBOX_IT max_it; //copy iterator
FPSEGPT_IT segpt_it; //iterator
//output segments
FPSEGPT_IT outseg_it = seg_list;
FPSEGPT_LIST_CLIST lattice; //list of lists
//region iterator
FPSEGPT_LIST_C_IT lattice_it = &lattice;
// tprintf("Computing sync on word of %d blobs with pitch %d\n",
// blob_count, pitch);
// if (blob_count==8 && pitch==27)
// projection->print(stdout,true);
if (pitch < 3)
pitch = 3; //nothing ludicrous
if ((pitch - 3) / 2 < pitch_error)
pitch_error = (pitch - 3) / 2;
min_it = *blob_it;
min_box = box_next (&min_it); //get box
// if (blob_count==8 && pitch==27)
// tprintf("1st box at (%d,%d)->(%d,%d)\n",
// min_box.left(),min_box.bottom(),
// min_box.right(),min_box.top());
//left of word
left_edge = min_box.left () + pitch_error;
for (min_index = 1; min_index < blob_count; min_index++) {
min_box = box_next (&min_it);
// if (blob_count==8 && pitch==27)
// tprintf("Box at (%d,%d)->(%d,%d)\n",
// min_box.left(),min_box.bottom(),
// min_box.right(),min_box.top());
}
right_edge = min_box.right (); //end of word
max_x = left_edge;
//min permissible
min_x = max_x - pitch + pitch_error * 2 + 1;
right_max = right_edge + pitch - pitch_error - 1;
segpts = new FPSEGPT_LIST; //list of points
segpt_it.set_to_list (segpts);
for (x = min_x; x <= max_x; x++) {
segpt = new FPSEGPT (x); //make a new one
//put in list
segpt_it.add_after_then_move (segpt);
}
//first segment
lattice_it.add_before_then_move (segpts);
min_index = 0;
region_index = 1;
best_cost = FLT_MAX;
best_end = nullptr;
min_it = *blob_it;
min_box = box_next (&min_it); //first box
do {
left_best_x = -1;
right_best_x = -1;
segpts = new FPSEGPT_LIST; //list of points
segpt_it.set_to_list (segpts);
min_x += pitch - pitch_error;//next limits
max_x += pitch + pitch_error;
while (min_box.right () < min_x && min_index < blob_count) {
min_index++;
min_box = box_next (&min_it);
}
max_it = min_it;
max_index = min_index;
max_box = min_box;
next_box = box_next (&max_it);
for (x = min_x; x <= max_x && x <= right_max; x++) {
while (x < right_edge && max_index < blob_count
&& x > max_box.right ()) {
max_index++;
max_box = next_box;
next_box = box_next (&max_it);
}
if (x <= max_box.left () + pitch_error
|| x >= max_box.right () - pitch_error || x >= right_edge
|| (max_index < blob_count - 1 && x >= next_box.left ())
|| (x - max_box.left () > pitch * pitsync_joined_edge
&& max_box.right () - x > pitch * pitsync_joined_edge)) {
// || projection->local_min(x))
if (x - max_box.left () > 0
&& x - max_box.left () <= pitch_error)
//dist to real break
offset = x - max_box.left ();
else if (max_box.right () - x > 0
&& max_box.right () - x <= pitch_error
&& (max_index >= blob_count - 1
|| x < next_box.left ()))
offset = max_box.right () - x;
else
offset = 0;
// offset=pitsync_offset_freecut_fraction*projection->pile_count(x);
segpt = new FPSEGPT (x, false, offset, region_index,
pitch, pitch_error, lattice_it.data ());
}
else {
offset = projection->pile_count (x);
segpt = new FPSEGPT (x, true, offset, region_index,
pitch, pitch_error, lattice_it.data ());
}
if (segpt->previous () != nullptr) {
segpt_it.add_after_then_move (segpt);
if (x >= right_edge - pitch_error) {
segpt->terminal = true;//no more wanted
if (segpt->cost_function () < best_cost) {
best_cost = segpt->cost_function ();
//find least
best_end = segpt;
best_region_index = region_index;
left_best_x = x;
right_best_x = x;
}
else if (segpt->cost_function () == best_cost
&& right_best_x == x - 1)
right_best_x = x;
}
}
else {
delete segpt; //no good
}
}
if (segpts->empty ()) {
if (best_end != nullptr)
break; //already found one
make_illegal_segment (lattice_it.data (), min_box, min_it,
region_index, pitch, pitch_error, segpts);
}
else {
if (right_best_x > left_best_x + 1) {
left_best_x = (left_best_x + right_best_x + 1) / 2;
for (segpt_it.mark_cycle_pt (); !segpt_it.cycled_list ()
&& segpt_it.data ()->position () != left_best_x;
segpt_it.forward ());
if (segpt_it.data ()->position () == left_best_x)
//middle of region
best_end = segpt_it.data ();
}
}
//new segment
lattice_it.add_before_then_move (segpts);
region_index++;
}
while (min_x < right_edge);
ASSERT_HOST (best_end != nullptr);//must always find some
for (lattice_it.mark_cycle_pt (); !lattice_it.cycled_list ();
lattice_it.forward ()) {
segpts = lattice_it.data ();
segpt_it.set_to_list (segpts);
// if (blob_count==8 && pitch==27)
// {
// for (segpt_it.mark_cycle_pt();!segpt_it.cycled_list();segpt_it.forward())
// {
// segpt=segpt_it.data();
// tprintf("At %d, (%x) cost=%g, m=%g, sq=%g, pred=%x\n",
// segpt->position(),segpt,segpt->cost_function(),
// segpt->sum(),segpt->squares(),segpt->previous());
// }
// tprintf("\n");
// }
for (segpt_it.mark_cycle_pt (); !segpt_it.cycled_list ()
&& segpt_it.data () != best_end; segpt_it.forward ());
if (segpt_it.data () == best_end) {
//save good one
segpt = segpt_it.extract ();
outseg_it.add_before_then_move (segpt);
best_end = segpt->previous ();
}
}
ASSERT_HOST (best_end == nullptr);
ASSERT_HOST (!outseg_it.empty ());
outseg_it.move_to_last ();
mean_sum = outseg_it.data ()->sum ();
mean_sum = mean_sum * mean_sum / best_region_index;
if (outseg_it.data ()->squares () - mean_sum < 0)
tprintf ("Impossible sqsum=%g, mean=%g, total=%d\n",
outseg_it.data ()->squares (), outseg_it.data ()->sum (),
best_region_index);
lattice.deep_clear (); //shift the lot
return outseg_it.data ()->squares () - mean_sum;
}
/**********************************************************************
* make_illegal_segment
*
* Make a fake set of chop points due to having no legal places.
**********************************************************************/
void make_illegal_segment( //find segmentation
FPSEGPT_LIST *prev_list, //previous segments
TBOX blob_box, //bounding box
BLOBNBOX_IT blob_it, //iterator
int16_t region_index, //number of segment
int16_t pitch, //pitch estimate
int16_t pitch_error, //tolerance
FPSEGPT_LIST *seg_list //output list
) {
int16_t x; //current coord
int16_t min_x = 0; //in this region
int16_t max_x = 0;
int16_t offset; //dist to edge
FPSEGPT *segpt; //segment point
FPSEGPT *prevpt; //previous point
float best_cost; //best path
FPSEGPT_IT segpt_it = seg_list;//iterator
//previous points
FPSEGPT_IT prevpt_it = prev_list;
best_cost = FLT_MAX;
for (prevpt_it.mark_cycle_pt (); !prevpt_it.cycled_list ();
prevpt_it.forward ()) {
prevpt = prevpt_it.data ();
if (prevpt->cost_function () < best_cost) {
//find least
best_cost = prevpt->cost_function ();
min_x = prevpt->position ();
max_x = min_x; //limits on coords
}
else if (prevpt->cost_function () == best_cost) {
max_x = prevpt->position ();
}
}
min_x += pitch - pitch_error;
max_x += pitch + pitch_error;
for (x = min_x; x <= max_x; x++) {
while (x > blob_box.right ()) {
blob_box = box_next (&blob_it);
}
offset = x - blob_box.left ();
if (blob_box.right () - x < offset)
offset = blob_box.right () - x;
segpt = new FPSEGPT (x, false, offset,
region_index, pitch, pitch_error, prev_list);
if (segpt->previous () != nullptr) {
ASSERT_HOST (offset >= 0);
fprintf (stderr, "made fake at %d\n", x);
//make one up
segpt_it.add_after_then_move (segpt);
segpt->faked = true;
segpt->fake_count++;
}
else
delete segpt;
}
}
} // namespace tesseract
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