mirror of
https://github.com/tesseract-ocr/tesseract.git
synced 2024-11-27 20:59:36 +08:00
81 lines
2.6 KiB
C++
81 lines
2.6 KiB
C++
/**********************************************************************
|
|
* File: ligature_table.h
|
|
* Description: Class for adding and removing optional latin ligatures,
|
|
* conditional on codepoint support by a specified font
|
|
* (if specified).
|
|
* Author: Ranjith Unnikrishnan
|
|
* Created: Mon Nov 18 2013
|
|
*
|
|
* (C) Copyright 2013, 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 TRAININGDATA_LIGATURE_TABLE_H_
|
|
#define TRAININGDATA_LIGATURE_TABLE_H_
|
|
|
|
#include <memory>
|
|
#include <string>
|
|
#include <unordered_map>
|
|
|
|
#include "util.h"
|
|
|
|
namespace tesseract {
|
|
|
|
class PangoFontInfo; // defined in pango_font_info.h
|
|
|
|
// Map to substitute strings for ligatures.
|
|
typedef std::unordered_map<string, string, StringHash> LigHash;
|
|
|
|
class LigatureTable {
|
|
public:
|
|
// Get a static instance of this class.
|
|
static LigatureTable* Get();
|
|
|
|
// Convert the utf8 string so that ligaturizable sequences, such as "fi" get
|
|
// replaced by the (utf8 code for) appropriate ligature characters. Only do so
|
|
// if the corresponding ligature character is renderable in the current font.
|
|
string AddLigatures(const string& str, const PangoFontInfo* font) const;
|
|
// Remove all ligatures.
|
|
string RemoveLigatures(const string& str) const;
|
|
// Remove only custom ligatures (eg. "ct") encoded in the private-use-area.
|
|
string RemoveCustomLigatures(const string& str) const;
|
|
|
|
const LigHash& norm_to_lig_table() const {
|
|
return norm_to_lig_table_;
|
|
}
|
|
const LigHash& lig_to_norm_table() const {
|
|
return lig_to_norm_table_;
|
|
}
|
|
|
|
protected:
|
|
LigatureTable();
|
|
// Initialize the hash tables mapping between ligature strings and the
|
|
// corresponding ligature characters.
|
|
void Init();
|
|
|
|
static std::unique_ptr<LigatureTable> instance_;
|
|
LigHash norm_to_lig_table_;
|
|
LigHash lig_to_norm_table_;
|
|
int min_lig_length_;
|
|
int max_lig_length_;
|
|
int min_norm_length_;
|
|
int max_norm_length_;
|
|
|
|
private:
|
|
LigatureTable(const LigatureTable&);
|
|
void operator=(const LigatureTable&);
|
|
};
|
|
|
|
} // namespace tesseract
|
|
|
|
#endif // OCR_TRAININGDATA_TYPESETTING_LIGATURE_TABLE_H_
|