tesseract/ccutil/tessdatamanager.h
2016-12-13 14:37:40 -08:00

326 lines
12 KiB
C++

///////////////////////////////////////////////////////////////////////
// File: tessdatamanager.h
// Description: Functions to handle loading/combining tesseract data files.
// Author: Daria Antonova
// Created: Wed Jun 03 11:26:43 PST 2009
//
// (C) Copyright 2009, 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_CCUTIL_TESSDATAMANAGER_H_
#define TESSERACT_CCUTIL_TESSDATAMANAGER_H_
#include <stdio.h>
#include "host.h"
#include "strngs.h"
#include "tprintf.h"
static const char kTrainedDataSuffix[] = "traineddata";
// When adding new tessdata types and file suffixes, please make sure to
// update TessdataType enum, kTessdataFileSuffixes and kTessdataFileIsText.
static const char kLangConfigFileSuffix[] = "config";
static const char kUnicharsetFileSuffix[] = "unicharset";
static const char kAmbigsFileSuffix[] = "unicharambigs";
static const char kBuiltInTemplatesFileSuffix[] = "inttemp";
static const char kBuiltInCutoffsFileSuffix[] = "pffmtable";
static const char kNormProtoFileSuffix[] = "normproto";
static const char kPuncDawgFileSuffix[] = "punc-dawg";
static const char kSystemDawgFileSuffix[] = "word-dawg";
static const char kNumberDawgFileSuffix[] = "number-dawg";
static const char kFreqDawgFileSuffix[] = "freq-dawg";
static const char kFixedLengthDawgsFileSuffix[] = "fixed-length-dawgs";
static const char kCubeUnicharsetFileSuffix[] = "cube-unicharset";
static const char kCubeSystemDawgFileSuffix[] = "cube-word-dawg";
static const char kShapeTableFileSuffix[] = "shapetable";
static const char kBigramDawgFileSuffix[] = "bigram-dawg";
static const char kUnambigDawgFileSuffix[] = "unambig-dawg";
static const char kParamsModelFileSuffix[] = "params-model";
static const char kLSTMModelFileSuffix[] = "lstm";
static const char kLSTMPuncDawgFileSuffix[] = "lstm-punc-dawg";
static const char kLSTMSystemDawgFileSuffix[] = "lstm-word-dawg";
static const char kLSTMNumberDawgFileSuffix[] = "lstm-number-dawg";
namespace tesseract {
enum TessdataType {
TESSDATA_LANG_CONFIG, // 0
TESSDATA_UNICHARSET, // 1
TESSDATA_AMBIGS, // 2
TESSDATA_INTTEMP, // 3
TESSDATA_PFFMTABLE, // 4
TESSDATA_NORMPROTO, // 5
TESSDATA_PUNC_DAWG, // 6
TESSDATA_SYSTEM_DAWG, // 7
TESSDATA_NUMBER_DAWG, // 8
TESSDATA_FREQ_DAWG, // 9
TESSDATA_FIXED_LENGTH_DAWGS, // 10 // deprecated
TESSDATA_CUBE_UNICHARSET, // 11 // deprecated
TESSDATA_CUBE_SYSTEM_DAWG, // 12 // deprecated
TESSDATA_SHAPE_TABLE, // 13
TESSDATA_BIGRAM_DAWG, // 14
TESSDATA_UNAMBIG_DAWG, // 15
TESSDATA_PARAMS_MODEL, // 16
TESSDATA_LSTM, // 17
TESSDATA_LSTM_PUNC_DAWG, // 18
TESSDATA_LSTM_SYSTEM_DAWG, // 19
TESSDATA_LSTM_NUMBER_DAWG, // 20
TESSDATA_NUM_ENTRIES
};
/**
* kTessdataFileSuffixes[i] indicates the file suffix for
* tessdata of type i (from TessdataType enum).
*/
static const char *const kTessdataFileSuffixes[] = {
kLangConfigFileSuffix, // 0
kUnicharsetFileSuffix, // 1
kAmbigsFileSuffix, // 2
kBuiltInTemplatesFileSuffix, // 3
kBuiltInCutoffsFileSuffix, // 4
kNormProtoFileSuffix, // 5
kPuncDawgFileSuffix, // 6
kSystemDawgFileSuffix, // 7
kNumberDawgFileSuffix, // 8
kFreqDawgFileSuffix, // 9
kFixedLengthDawgsFileSuffix, // 10 // deprecated
kCubeUnicharsetFileSuffix, // 11 // deprecated
kCubeSystemDawgFileSuffix, // 12 // deprecated
kShapeTableFileSuffix, // 13
kBigramDawgFileSuffix, // 14
kUnambigDawgFileSuffix, // 15
kParamsModelFileSuffix, // 16
kLSTMModelFileSuffix, // 17
kLSTMPuncDawgFileSuffix, // 18
kLSTMSystemDawgFileSuffix, // 19
kLSTMNumberDawgFileSuffix, // 20
};
/**
* If kTessdataFileIsText[i] is true - the tessdata component
* of type i (from TessdataType enum) is text, and is binary otherwise.
*/
static const bool kTessdataFileIsText[] = {
true, // 0
true, // 1
true, // 2
false, // 3
true, // 4
true, // 5
false, // 6
false, // 7
false, // 8
false, // 9
false, // 10 // deprecated
true, // 11 // deprecated
false, // 12 // deprecated
false, // 13
false, // 14
false, // 15
true, // 16
false, // 17
false, // 18
false, // 19
false, // 20
};
/**
* TessdataType could be updated to contain more entries, however
* we do not expect that number to be astronomically high.
* In order to automatically detect endianness TessdataManager will
* flip the bits if actual_tessdata_num_entries_ is larger than
* kMaxNumTessdataEntries.
*/
static const int kMaxNumTessdataEntries = 1000;
class TessdataManager {
public:
TessdataManager() {
data_file_ = NULL;
actual_tessdata_num_entries_ = 0;
for (int i = 0; i < TESSDATA_NUM_ENTRIES; ++i) {
offset_table_[i] = -1;
}
}
~TessdataManager() {}
int DebugLevel() { return debug_level_; }
/**
* Opens the given data file and reads the offset table.
* @return true on success.
*/
bool Init(const char *data_file_name, int debug_level);
// Returns true if the base Tesseract components are present.
bool IsBaseAvailable() const { return IncludesBaseComponents(offset_table_); }
// Returns true if the LSTM components are present.
bool IsLSTMAvailable() const { return IncludesLSTMComponents(offset_table_); }
// Return the name of the underlying data file.
const STRING &GetDataFileName() const { return data_file_name_; }
/** Returns data file pointer. */
inline FILE *GetDataFilePtr() const { return data_file_; }
/**
* Returns false if there is no data of the given type.
* Otherwise does a seek on the data_file_ to position the pointer
* at the start of the data of the given type.
*/
inline bool SeekToStart(TessdataType tessdata_type) {
if (debug_level_) {
tprintf("TessdataManager: seek to offset %lld - start of tessdata"
"type %d (%s))\n", offset_table_[tessdata_type],
tessdata_type, kTessdataFileSuffixes[tessdata_type]);
}
if (offset_table_[tessdata_type] < 0) {
return false;
} else {
ASSERT_HOST(fseek(data_file_,
static_cast<size_t>(offset_table_[tessdata_type]),
SEEK_SET) == 0);
return true;
}
}
/** Returns the end offset for the given tesseract data file type. */
inline inT64 GetEndOffset(TessdataType tessdata_type) const {
int index = tessdata_type + 1;
while (index < actual_tessdata_num_entries_ && offset_table_[index] == -1) {
++index; // skip tessdata types not present in the combined file
}
if (debug_level_) {
tprintf("TessdataManager: end offset for type %d is %lld\n",
tessdata_type,
(index == actual_tessdata_num_entries_) ? -1
: offset_table_[index]);
}
return (index == actual_tessdata_num_entries_) ? -1 : offset_table_[index] - 1;
}
/** Closes data_file_ (if it was opened by Init()). */
inline void End() {
if (data_file_ != NULL) {
fclose(data_file_);
data_file_ = NULL;
}
}
bool swap() const {
return swap_;
}
/** Writes the number of entries and the given offset table to output_file.
* Returns false on error.
*/
static bool WriteMetadata(inT64 *offset_table,
const char *language_data_path_prefix,
FILE *output_file);
/**
* Reads all the standard tesseract config and data files for a language
* at the given path and bundles them up into one binary data file.
* Returns true if the combined traineddata file was successfully written.
*/
static bool CombineDataFiles(const char *language_data_path_prefix,
const char *output_filename);
/**
* Gets the individual components from the data_file_ with which the class was
* initialized. Overwrites the components specified by component_filenames.
* Writes the updated traineddata file to new_traineddata_filename.
*/
bool OverwriteComponents(const char *new_traineddata_filename,
char **component_filenames,
int num_new_components);
/**
* Extracts tessdata component implied by the name of the input file from
* the combined traineddata loaded into TessdataManager.
* Writes the extracted component to the file indicated by the file name.
* E.g. if the filename given is somepath/somelang.unicharset, unicharset
* will be extracted from the data loaded into the TessdataManager and will
* be written to somepath/somelang.unicharset.
* @return true if the component was successfully extracted, false if the
* component was not present in the traineddata loaded into TessdataManager.
*/
bool ExtractToFile(const char *filename);
/**
* Copies data from the given input file to the output_file provided.
* If num_bytes_to_copy is >= 0, only num_bytes_to_copy is copied from
* the input file, otherwise all the data in the input file is copied.
*/
static void CopyFile(FILE *input_file, FILE *output_file,
bool newline_end, inT64 num_bytes_to_copy);
/**
* Fills type with TessdataType of the tessdata component represented by the
* given file name. E.g. tessdata/eng.unicharset -> TESSDATA_UNICHARSET.
* Sets *text_file to true if the component is in text format (e.g.
* unicharset, unichar ambigs, config, etc).
* @return true if the tessdata component type could be determined
* from the given file name.
*/
static bool TessdataTypeFromFileSuffix(const char *suffix,
TessdataType *type,
bool *text_file);
/**
* Tries to determine tessdata component file suffix from filename,
* returns true on success.
*/
static bool TessdataTypeFromFileName(const char *filename,
TessdataType *type,
bool *text_file);
private:
// Returns true if the base Tesseract components are present.
static bool IncludesBaseComponents(const inT64 *offset_table);
// Returns true if the LSTM components are present.
static bool IncludesLSTMComponents(const inT64 *offset_table);
/**
* Opens the file whose name is a concatenation of language_data_path_prefix
* and file_suffix. Returns a file pointer to the opened file.
*/
static FILE *GetFilePtr(const char *language_data_path_prefix,
const char *file_suffix, bool text_file);
/**
* Each offset_table_[i] contains a file offset in the combined data file
* where the data of TessdataFileType i is stored.
*/
inT64 offset_table_[TESSDATA_NUM_ENTRIES];
/**
* Actual number of entries in the tessdata table. This value can only be
* same or smaller than TESSDATA_NUM_ENTRIES, but can never be larger,
* since then it would be impossible to interpret the type of tessdata at
* indices same and higher than TESSDATA_NUM_ENTRIES.
* This parameter is used to allow for backward compatibility
* when new tessdata types are introduced.
*/
inT32 actual_tessdata_num_entries_;
STRING data_file_name_; // name of the data file.
FILE *data_file_; ///< pointer to the data file.
int debug_level_;
// True if the bytes need swapping.
bool swap_;
};
} // namespace tesseract
#endif // TESSERACT_CCUTIL_TESSDATAMANAGER_H_