tesseract  4.0.0-1-g2a2b
OrientationDetector Class Reference

#include <osdetect.h>

Public Member Functions

 OrientationDetector (const GenericVector< int > *allowed_scripts, OSResults *results)
 
bool detect_blob (BLOB_CHOICE_LIST *scores)
 
int get_orientation ()
 

Detailed Description

Definition at line 84 of file osdetect.h.

Constructor & Destructor Documentation

◆ OrientationDetector()

OrientationDetector::OrientationDetector ( const GenericVector< int > *  allowed_scripts,
OSResults results 
)

Definition at line 374 of file osdetect.cpp.

375  {
376  osr_ = osr;
377  allowed_scripts_ = allowed_scripts;
378 }

Member Function Documentation

◆ detect_blob()

bool OrientationDetector::detect_blob ( BLOB_CHOICE_LIST *  scores)

Definition at line 382 of file osdetect.cpp.

382  {
383  float blob_o_score[4] = {0.0f, 0.0f, 0.0f, 0.0f};
384  float total_blob_o_score = 0.0f;
385 
386  for (int i = 0; i < 4; ++i) {
387  BLOB_CHOICE_IT choice_it(scores + i);
388  if (!choice_it.empty()) {
389  BLOB_CHOICE* choice = nullptr;
390  if (allowed_scripts_ != nullptr && !allowed_scripts_->empty()) {
391  // Find the top choice in an allowed script.
392  for (choice_it.mark_cycle_pt(); !choice_it.cycled_list() &&
393  choice == nullptr; choice_it.forward()) {
394  int choice_script = choice_it.data()->script_id();
395  int s = 0;
396  for (s = 0; s < allowed_scripts_->size(); ++s) {
397  if ((*allowed_scripts_)[s] == choice_script) {
398  choice = choice_it.data();
399  break;
400  }
401  }
402  }
403  } else {
404  choice = choice_it.data();
405  }
406  if (choice != nullptr) {
407  // The certainty score ranges between [-20,0]. This is converted here to
408  // [0,1], with 1 indicating best match.
409  blob_o_score[i] = 1 + 0.05 * choice->certainty();
410  total_blob_o_score += blob_o_score[i];
411  }
412  }
413  }
414  if (total_blob_o_score == 0.0) return false;
415  // Fill in any blanks with the worst score of the others. This is better than
416  // picking an arbitrary probability for it and way better than -inf.
417  float worst_score = 0.0f;
418  int num_good_scores = 0;
419  for (int i = 0; i < 4; ++i) {
420  if (blob_o_score[i] > 0.0f) {
421  ++num_good_scores;
422  if (worst_score == 0.0f || blob_o_score[i] < worst_score)
423  worst_score = blob_o_score[i];
424  }
425  }
426  if (num_good_scores == 1) {
427  // Lower worst if there is only one.
428  worst_score /= 2.0f;
429  }
430  for (int i = 0; i < 4; ++i) {
431  if (blob_o_score[i] == 0.0f) {
432  blob_o_score[i] = worst_score;
433  total_blob_o_score += worst_score;
434  }
435  }
436  // Normalize the orientation scores for the blob and use them to
437  // update the aggregated orientation score.
438  for (int i = 0; total_blob_o_score != 0 && i < 4; ++i) {
439  osr_->orientations[i] += log(blob_o_score[i] / total_blob_o_score);
440  }
441 
442  // TODO(ranjith) Add an early exit test, based on min_orientation_margin,
443  // as used in pagesegmain.cpp.
444  return false;
445 }
float certainty() const
Definition: ratngs.h:83
int size() const
Definition: genericvector.h:71
float orientations[4]
Definition: osdetect.h:76
bool empty() const
Definition: genericvector.h:90
int script_id() const
Definition: ratngs.h:112

◆ get_orientation()

int OrientationDetector::get_orientation ( )

Definition at line 447 of file osdetect.cpp.

447  {
448  osr_->update_best_orientation();
449  return osr_->best_result.orientation_id;
450 }
void update_best_orientation()
Definition: osdetect.cpp:62
OSBestResult best_result
Definition: osdetect.h:81
int orientation_id
Definition: osdetect.h:43

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