tesseract/include/tesseract/ltrresultiterator.h
Stefan Weil 7fe5248d91 Format public API files with modified rules for clang-format
Disable clang-format for version.h.in because it destroys
several macro definitions.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
2021-04-07 18:53:48 +02:00

242 lines
10 KiB
C++

///////////////////////////////////////////////////////////////////////
// File: ltrresultiterator.h
// Description: Iterator for tesseract results in strict left-to-right
// order that avoids using tesseract internal data structures.
// Author: Ray Smith
//
// (C) Copyright 2010, Google Inc.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
///////////////////////////////////////////////////////////////////////
#ifndef TESSERACT_CCMAIN_LTR_RESULT_ITERATOR_H_
#define TESSERACT_CCMAIN_LTR_RESULT_ITERATOR_H_
#include "export.h" // for TESS_API
#include "pageiterator.h" // for PageIterator
#include "publictypes.h" // for PageIteratorLevel
#include "unichar.h" // for StrongScriptDirection
namespace tesseract {
class BLOB_CHOICE_IT;
class PAGE_RES;
class WERD_RES;
class Tesseract;
// Class to iterate over tesseract results, providing access to all levels
// of the page hierarchy, without including any tesseract headers or having
// to handle any tesseract structures.
// WARNING! This class points to data held within the TessBaseAPI class, and
// therefore can only be used while the TessBaseAPI class still exists and
// has not been subjected to a call of Init, SetImage, Recognize, Clear, End
// DetectOS, or anything else that changes the internal PAGE_RES.
// See tesseract/publictypes.h for the definition of PageIteratorLevel.
// See also base class PageIterator, which contains the bulk of the interface.
// LTRResultIterator adds text-specific methods for access to OCR output.
class TESS_API LTRResultIterator : public PageIterator {
friend class ChoiceIterator;
public:
// page_res and tesseract come directly from the BaseAPI.
// The rectangle parameters are copied indirectly from the Thresholder,
// via the BaseAPI. They represent the coordinates of some rectangle in an
// original image (in top-left-origin coordinates) and therefore the top-left
// needs to be added to any output boxes in order to specify coordinates
// in the original image. See TessBaseAPI::SetRectangle.
// The scale and scaled_yres are in case the Thresholder scaled the image
// rectangle prior to thresholding. Any coordinates in tesseract's image
// must be divided by scale before adding (rect_left, rect_top).
// The scaled_yres indicates the effective resolution of the binary image
// that tesseract has been given by the Thresholder.
// After the constructor, Begin has already been called.
LTRResultIterator(PAGE_RES *page_res, Tesseract *tesseract, int scale,
int scaled_yres, int rect_left, int rect_top,
int rect_width, int rect_height);
~LTRResultIterator() override;
// LTRResultIterators may be copied! This makes it possible to iterate over
// all the objects at a lower level, while maintaining an iterator to
// objects at a higher level. These constructors DO NOT CALL Begin, so
// iterations will continue from the location of src.
// TODO: For now the copy constructor and operator= only need the base class
// versions, but if new data members are added, don't forget to add them!
// ============= Moving around within the page ============.
// See PageIterator.
// ============= Accessing data ==============.
// Returns the null terminated UTF-8 encoded text string for the current
// object at the given level. Use delete [] to free after use.
char *GetUTF8Text(PageIteratorLevel level) const;
// Set the string inserted at the end of each text line. "\n" by default.
void SetLineSeparator(const char *new_line);
// Set the string inserted at the end of each paragraph. "\n" by default.
void SetParagraphSeparator(const char *new_para);
// Returns the mean confidence of the current object at the given level.
// The number should be interpreted as a percent probability. (0.0f-100.0f)
float Confidence(PageIteratorLevel level) const;
// Returns the attributes of the current row.
void RowAttributes(float *row_height, float *descenders,
float *ascenders) const;
// ============= Functions that refer to words only ============.
// Returns the font attributes of the current word. If iterating at a higher
// level object than words, eg textlines, then this will return the
// attributes of the first word in that textline.
// The actual return value is a string representing a font name. It points
// to an internal table and SHOULD NOT BE DELETED. Lifespan is the same as
// the iterator itself, ie rendered invalid by various members of
// TessBaseAPI, including Init, SetImage, End or deleting the TessBaseAPI.
// Pointsize is returned in printers points (1/72 inch.)
const char *WordFontAttributes(bool *is_bold, bool *is_italic,
bool *is_underlined, bool *is_monospace,
bool *is_serif, bool *is_smallcaps,
int *pointsize, int *font_id) const;
// Return the name of the language used to recognize this word.
// On error, nullptr. Do not delete this pointer.
const char *WordRecognitionLanguage() const;
// Return the overall directionality of this word.
StrongScriptDirection WordDirection() const;
// Returns true if the current word was found in a dictionary.
bool WordIsFromDictionary() const;
// Returns the number of blanks before the current word.
int BlanksBeforeWord() const;
// Returns true if the current word is numeric.
bool WordIsNumeric() const;
// Returns true if the word contains blamer information.
bool HasBlamerInfo() const;
// Returns the pointer to ParamsTrainingBundle stored in the BlamerBundle
// of the current word.
const void *GetParamsTrainingBundle() const;
// Returns a pointer to the string with blamer information for this word.
// Assumes that the word's blamer_bundle is not nullptr.
const char *GetBlamerDebug() const;
// Returns a pointer to the string with misadaption information for this word.
// Assumes that the word's blamer_bundle is not nullptr.
const char *GetBlamerMisadaptionDebug() const;
// Returns true if a truth string was recorded for the current word.
bool HasTruthString() const;
// Returns true if the given string is equivalent to the truth string for
// the current word.
bool EquivalentToTruth(const char *str) const;
// Returns a null terminated UTF-8 encoded truth string for the current word.
// Use delete [] to free after use.
char *WordTruthUTF8Text() const;
// Returns a null terminated UTF-8 encoded normalized OCR string for the
// current word. Use delete [] to free after use.
char *WordNormedUTF8Text() const;
// Returns a pointer to serialized choice lattice.
// Fills lattice_size with the number of bytes in lattice data.
const char *WordLattice(int *lattice_size) const;
// ============= Functions that refer to symbols only ============.
// Returns true if the current symbol is a superscript.
// If iterating at a higher level object than symbols, eg words, then
// this will return the attributes of the first symbol in that word.
bool SymbolIsSuperscript() const;
// Returns true if the current symbol is a subscript.
// If iterating at a higher level object than symbols, eg words, then
// this will return the attributes of the first symbol in that word.
bool SymbolIsSubscript() const;
// Returns true if the current symbol is a dropcap.
// If iterating at a higher level object than symbols, eg words, then
// this will return the attributes of the first symbol in that word.
bool SymbolIsDropcap() const;
protected:
const char *line_separator_;
const char *paragraph_separator_;
};
// Class to iterate over the classifier choices for a single RIL_SYMBOL.
class TESS_API ChoiceIterator {
public:
// Construction is from a LTRResultIterator that points to the symbol of
// interest. The ChoiceIterator allows a one-shot iteration over the
// choices for this symbol and after that is is useless.
explicit ChoiceIterator(const LTRResultIterator &result_it);
~ChoiceIterator();
// Moves to the next choice for the symbol and returns false if there
// are none left.
bool Next();
// ============= Accessing data ==============.
// Returns the null terminated UTF-8 encoded text string for the current
// choice.
// NOTE: Unlike LTRResultIterator::GetUTF8Text, the return points to an
// internal structure and should NOT be delete[]ed to free after use.
const char *GetUTF8Text() const;
// Returns the confidence of the current choice depending on the used language
// data. If only LSTM traineddata is used the value range is 0.0f - 1.0f. All
// choices for one symbol should roughly add up to 1.0f.
// If only traineddata of the legacy engine is used, the number should be
// interpreted as a percent probability. (0.0f-100.0f) In this case
// probabilities won't add up to 100. Each one stands on its own.
float Confidence() const;
// Returns a vector containing all timesteps, which belong to the currently
// selected symbol. A timestep is a vector containing pairs of symbols and
// floating point numbers. The number states the probability for the
// corresponding symbol.
std::vector<std::vector<std::pair<const char *, float>>> *Timesteps() const;
private:
// clears the remaining spaces out of the results and adapt the probabilities
void filterSpaces();
// Pointer to the WERD_RES object owned by the API.
WERD_RES *word_res_;
// Iterator over the blob choices.
BLOB_CHOICE_IT *choice_it_;
std::vector<std::pair<const char *, float>> *LSTM_choices_ = nullptr;
std::vector<std::pair<const char *, float>>::iterator LSTM_choice_it_;
const int *tstep_index_;
// regulates the rating granularity
double rating_coefficient_;
// leading blanks
int blanks_before_word_;
// true when there is lstm engine related trained data
bool oemLSTM_;
};
} // namespace tesseract.
#endif // TESSERACT_CCMAIN_LTR_RESULT_ITERATOR_H_