/// Resegments the word to achieve the target_text from the classifier.
/// Returns false if the re-segmentation fails.
/// Uses brute-force combination of up to #kMaxGroupSize adjacent blobs, and
/// applies a full search on the classifier results to find the best classified
/// segmentation. As a compromise to obtain better recall, 1-1 ambiguity
/// substitutions ARE used.
bool Tesseract::FindSegmentation(const GenericVector<UNICHAR_ID>& target_text,
WERD_RES* word_res) {
// Classify all required combinations of blobs and save results in choices.
int word_length = word_res->box_word->length();
GenericVector<BLOB_CHOICE_LIST*>* choices =
new GenericVector<BLOB_CHOICE_LIST*>[word_length];
for (int i = 0; i < word_length; ++i) {
for (int j = 1; j <= kMaxGroupSize && i + j <= word_length; ++j) {
BLOB_CHOICE_LIST* match_result = classify_piece(
word_res->seam_array, i, i + j - 1, "Applybox",
word_res->chopped_word, word_res->blamer_bundle);
if (applybox_debug > 2) {
tprintf("%d+%d:", i, j);
print_ratings_list("Segment:", match_result, unicharset);
}
choices[i].push_back(match_result);
}
}
// Search the segmentation graph for the target text. Must be an exact
// match. Using wildcards makes it difficult to find the correct
// segmentation even when it is there.
word_res->best_state.clear();
GenericVector<int> search_segmentation;
float best_rating = 0.0f;
SearchForText(choices, 0, word_length, target_text, 0, 0.0f,
&search_segmentation, &best_rating, &word_res->best_state);
for (int i = 0; i < word_length; ++i)
choices[i].delete_data_pointers();
delete [] choices;
if (word_res->best_state.empty()) {
// Build the original segmentation and if it is the same length as the
// truth, assume it will do.
int blob_count = 1;
for (int s = 0; s < word_res->seam_array.size(); ++s) {
SEAM* seam = word_res->seam_array[s];
if (!seam->HasAnySplits()) {
word_res->best_state.push_back(blob_count);
blob_count = 1;
} else {
++blob_count;
}
}
word_res->best_state.push_back(blob_count);
if (word_res->best_state.size() != target_text.size()) {
word_res->best_state.clear(); // No good. Original segmentation bad size.
return false;
}
}
word_res->correct_text.clear();
for (int i = 0; i < target_text.size(); ++i) {
word_res->correct_text.push_back(
STRING(unicharset.id_to_unichar(target_text[i])));
}
return true;
}
/**
* @name attempt_blob_chop
*
* Try to split the this blob after this one. Check to make sure that
* it was successful.
*/
SEAM *Wordrec::attempt_blob_chop(TWERD *word, TBLOB *blob, int32_t blob_number,
bool italic_blob,
const GenericVector<SEAM*>& seams) {
if (repair_unchopped_blobs)
preserve_outline_tree (blob->outlines);
TBLOB *other_blob = TBLOB::ShallowCopy(*blob); /* Make new blob */
// Insert it into the word.
word->blobs.insert(other_blob, blob_number + 1);
SEAM *seam = nullptr;
if (prioritize_division) {
TPOINT location;
if (divisible_blob(blob, italic_blob, &location)) {
seam = new SEAM(0.0f, location);
}
}
if (seam == nullptr)
seam = pick_good_seam(blob);
if (chop_debug) {
if (seam != nullptr)
seam->Print("Good seam picked=");
else
tprintf("\n** no seam picked *** \n");
}
if (seam) {
seam->ApplySeam(italic_blob, blob, other_blob);
}
seam = CheckSeam(chop_debug, blob_number, word, blob, other_blob,
seams, seam);
if (seam == nullptr) {
if (repair_unchopped_blobs)
restore_outline_tree(blob->outlines);
if (allow_blob_division && !prioritize_division) {
// If the blob can simply be divided into outlines, then do that.
TPOINT location;
if (divisible_blob(blob, italic_blob, &location)) {
other_blob = TBLOB::ShallowCopy(*blob); /* Make new blob */
word->blobs.insert(other_blob, blob_number + 1);
seam = new SEAM(0.0f, location);
seam->ApplySeam(italic_blob, blob, other_blob);
seam = CheckSeam(chop_debug, blob_number, word, blob, other_blob,
seams, seam);
}
}
}
if (seam != nullptr) {
// Make sure this seam doesn't get chopped again.
seam->Finalize();
}
return seam;
}
/**********************************************************************
* pick_good_seam
*
* Find and return a good seam that will split this blob into two pieces.
* Work from the outlines provided.
**********************************************************************/
SEAM *Wordrec::pick_good_seam(TBLOB *blob) {
SeamPile seam_pile(chop_seam_pile_size);
EDGEPT *points[MAX_NUM_POINTS];
EDGEPT_CLIST new_points;
SEAM *seam = NULL;
TESSLINE *outline;
inT16 num_points = 0;
#ifndef GRAPHICS_DISABLED
if (chop_debug > 2)
wordrec_display_splits.set_value(true);
draw_blob_edges(blob);
#endif
PointHeap point_heap(MAX_NUM_POINTS);
for (outline = blob->outlines; outline; outline = outline->next)
prioritize_points(outline, &point_heap);
while (!point_heap.empty() && num_points < MAX_NUM_POINTS) {
points[num_points++] = point_heap.PeekTop().data;
point_heap.Pop(NULL);
}
/* Initialize queue */
SeamQueue seam_queue(MAX_NUM_SEAMS);
try_point_pairs(points, num_points, &seam_queue, &seam_pile, &seam, blob);
try_vertical_splits(points, num_points, &new_points,
&seam_queue, &seam_pile, &seam, blob);
if (seam == NULL) {
choose_best_seam(&seam_queue, NULL, BAD_PRIORITY, &seam, blob, &seam_pile);
} else if (seam->priority() > chop_good_split) {
choose_best_seam(&seam_queue, NULL, seam->priority(), &seam, blob,
&seam_pile);
}
EDGEPT_C_IT it(&new_points);
for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
EDGEPT *inserted_point = it.data();
if (seam == NULL || !seam->UsesPoint(inserted_point)) {
for (outline = blob->outlines; outline; outline = outline->next) {
if (outline->loop == inserted_point) {
outline->loop = outline->loop->next;
}
}
remove_edgept(inserted_point);
}
}
if (seam) {
if (seam->priority() > chop_ok_split) {
delete seam;
seam = NULL;
}
#ifndef GRAPHICS_DISABLED
else if (wordrec_display_splits) {
seam->Mark(edge_window);
if (chop_debug > 2) {
update_edge_window();
edge_window_wait();
}
}
#endif
}
if (chop_debug)
wordrec_display_splits.set_value(false);
return (seam);
}
/**********************************************************************
* choose_best_seam
*
* Choose the best seam that can be created by assembling this a
* collection of splits. A queue of all the possible seams is
* maintained. Each new split received is placed in that queue with
* its partial priority value. These values in the seam queue are
* evaluated and combined until a good enough seam is found. If no
* further good seams are being found then this function returns to the
* caller, who will send more splits. If this function is called with
* a split of NULL, then no further splits can be supplied by the
* caller.
**********************************************************************/
void Wordrec::choose_best_seam(SeamQueue *seam_queue, const SPLIT *split,
PRIORITY priority, SEAM **seam_result,
TBLOB *blob, SeamPile *seam_pile) {
SEAM *seam;
char str[80];
float my_priority;
/* Add seam of split */
my_priority = priority;
if (split != NULL) {
TPOINT split_point = split->point1->pos;
split_point += split->point2->pos;
split_point /= 2;
seam = new SEAM(my_priority, split_point, *split);
if (chop_debug > 1) seam->Print("Partial priority ");
add_seam_to_queue(my_priority, seam, seam_queue);
if (my_priority > chop_good_split)
return;
}
TBOX bbox = blob->bounding_box();
/* Queue loop */
while (!seam_queue->empty()) {
SeamPair seam_pair;
seam_queue->Pop(&seam_pair);
seam = seam_pair.extract_data();
/* Set full priority */
my_priority = seam->FullPriority(bbox.left(), bbox.right(),
chop_overlap_knob, chop_centered_maxwidth,
chop_center_knob, chop_width_change_knob);
if (chop_debug) {
sprintf (str, "Full my_priority %0.0f, ", my_priority);
seam->Print(str);
}
if ((*seam_result == NULL || (*seam_result)->priority() > my_priority) &&
my_priority < chop_ok_split) {
/* No crossing */
if (seam->IsHealthy(*blob, chop_min_outline_points,
chop_min_outline_area)) {
delete *seam_result;
*seam_result = new SEAM(*seam);
(*seam_result)->set_priority(my_priority);
} else {
delete seam;
seam = NULL;
my_priority = BAD_PRIORITY;
}
}
if (my_priority < chop_good_split) {
if (seam)
delete seam;
return; /* Made good answer */
}
if (seam) {
/* Combine with others */
if (seam_pile->size() < chop_seam_pile_size) {
combine_seam(*seam_pile, seam, seam_queue);
SeamDecPair pair(seam_pair.key(), seam);
seam_pile->Push(&pair);
} else if (chop_new_seam_pile &&
seam_pile->size() == chop_seam_pile_size &&
seam_pile->PeekTop().key() > seam_pair.key()) {
combine_seam(*seam_pile, seam, seam_queue);
SeamDecPair pair;
seam_pile->Pop(&pair); // pop the worst.
// Replace the seam in pair (deleting the old one) with
// the new seam and score, then push back into the heap.
pair.set_key(seam_pair.key());
pair.set_data(seam);
seam_pile->Push(&pair);
} else {
delete seam;
}
}
my_priority = seam_queue->empty() ? NO_FULL_PRIORITY
: seam_queue->PeekTop().key();
if ((my_priority > chop_ok_split) ||
(my_priority > chop_good_split && split))
return;
}
}
