tesseract/cube/tess_lang_mod_edge.h

234 lines
7.5 KiB
C++

/**********************************************************************
* File: tess_lang_mod_edge.h
* Description: Declaration of the Tesseract Language Model Edge Class
* Author: Ahmad Abdulkader
* Created: 2008
*
* (C) Copyright 2008, 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.
*
**********************************************************************/
// The TessLangModEdge models an edge in the Tesseract language models
// It inherits from the LangModEdge class
#ifndef TESS_LANG_MOD_EDGE_H
#define TESS_LANG_MOD_EDGE_H
#include "dawg.h"
#include "char_set.h"
#include "lang_mod_edge.h"
#include "cube_reco_context.h"
#include "cube_utils.h"
// Macros needed to identify punctuation in the langmodel state
#ifdef _HMSW32_H
#define LEAD_PUNC_EDGE_REF_MASK (inT64) 0x0000000100000000i64
#define TRAIL_PUNC_EDGE_REF_MASK (inT64) 0x0000000200000000i64
#define TRAIL_PUNC_REPEAT_MASK (inT64) 0xffff000000000000i64
#else
#define LEAD_PUNC_EDGE_REF_MASK (inT64) 0x0000000100000000ll
#define TRAIL_PUNC_EDGE_REF_MASK (inT64) 0x0000000200000000ll
#define TRAIL_PUNC_REPEAT_MASK (inT64) 0xffff000000000000ll
#endif
// Number state machine macros
#define NUMBER_STATE_SHIFT 0
#define NUMBER_STATE_MASK 0x0000000fl
#define NUMBER_LITERAL_SHIFT 4
#define NUMBER_LITERAL_MASK 0x000000f0l
#define NUMBER_REPEAT_SHIFT 8
#define NUMBER_REPEAT_MASK 0x00000f00l
#define NUM_TRM -99
#define TRAIL_PUNC_REPEAT_SHIFT 48
#define IsLeadingPuncEdge(edge_mask) \
((edge_mask & LEAD_PUNC_EDGE_REF_MASK) != 0)
#define IsTrailingPuncEdge(edge_mask) \
((edge_mask & TRAIL_PUNC_EDGE_REF_MASK) != 0)
#define TrailingPuncCount(edge_mask) \
((edge_mask & TRAIL_PUNC_REPEAT_MASK) >> TRAIL_PUNC_REPEAT_SHIFT)
#define TrailingPuncEdgeMask(Cnt) \
(TRAIL_PUNC_EDGE_REF_MASK | ((Cnt) << TRAIL_PUNC_REPEAT_SHIFT))
// State machine IDs
#define DAWG_OOD 0
#define DAWG_NUMBER 1
namespace tesseract {
class TessLangModEdge : public LangModEdge {
public:
// Different ways of constructing a TessLangModEdge
TessLangModEdge(CubeRecoContext *cntxt, const Dawg *edge_array,
EDGE_REF edge, int class_id);
TessLangModEdge(CubeRecoContext *cntxt, const Dawg *edge_array,
EDGE_REF start_edge_idx, EDGE_REF end_edge_idx,
int class_id);
TessLangModEdge(CubeRecoContext *cntxt, int class_id);
~TessLangModEdge() {}
// Accessors
inline bool IsRoot() const {
return root_;
}
inline void SetRoot(bool flag) { root_ = flag; }
inline bool IsOOD() const {
return (dawg_ == (Dawg *)DAWG_OOD);
}
inline bool IsNumber() const {
return (dawg_ == (Dawg *)DAWG_NUMBER);
}
inline bool IsEOW() const {
return (IsTerminal() || (dawg_->end_of_word(end_edge_) != 0));
}
inline const Dawg *GetDawg() const { return dawg_; }
inline EDGE_REF StartEdge() const { return start_edge_; }
inline EDGE_REF EndEdge() const { return end_edge_; }
inline EDGE_REF EdgeMask() const { return edge_mask_; }
inline const char_32 * EdgeString() const { return str_; }
inline int ClassID () const { return class_id_; }
inline int PathCost() const { return path_cost_; }
inline void SetEdgeMask(EDGE_REF edge_mask) { edge_mask_ = edge_mask; }
inline void SetDawg(Dawg *dawg) { dawg_ = dawg; }
inline void SetStartEdge(EDGE_REF edge_idx) { start_edge_ = edge_idx; }
inline void SetEndEdge(EDGE_REF edge_idx) { end_edge_ = edge_idx; }
// is this a terminal node:
// we can terminate at any OOD char, trailing punc or
// when the dawg terminates
inline bool IsTerminal() const {
return (IsOOD() || IsNumber() || IsTrailingPuncEdge(start_edge_) ||
dawg_->next_node(end_edge_) == 0);
}
// How many signals does the LM provide for tuning. These are flags like:
// OOD or not, Number of not that are used by the training to compute
// extra costs for each word.
inline int SignalCnt() const {
return 2;
}
// returns the weight assigned to a specified signal
inline double SignalWgt(int signal) const {
CubeTuningParams *params =
reinterpret_cast<CubeTuningParams *>(cntxt_->Params());
if (params != NULL) {
switch (signal) {
case 0:
return params->OODWgt();
break;
case 1:
return params->NumWgt();
break;
}
}
return 0.0;
}
// sets the weight assigned to a specified signal: Used in training
void SetSignalWgt(int signal, double wgt) {
CubeTuningParams *params =
reinterpret_cast<CubeTuningParams *>(cntxt_->Params());
if (params != NULL) {
switch (signal) {
case 0:
params->SetOODWgt(wgt);
break;
case 1:
params->SetNumWgt(wgt);
break;
}
}
}
// returns the actual value of a specified signal
int Signal(int signal) {
switch (signal) {
case 0:
return IsOOD() ? MIN_PROB_COST : 0;
break;
case 1:
return IsNumber() ? MIN_PROB_COST : 0;
break;
default:
return 0;
}
}
// returns the Hash value of the edge. Used by the SearchNode hash table
// to quickly lookup exisiting edges to converge during search
inline unsigned int Hash() const {
return static_cast<unsigned int>(
((start_edge_ | end_edge_) ^ ((reinterpret_cast<uintptr_t>(dawg_)))) ^
((unsigned int)edge_mask_) ^ class_id_);
}
// A verbal description of the edge: Used by visualizers
char *Description() const;
// Is this edge identical to the specified edge
inline bool IsIdentical(LangModEdge *lang_mod_edge) const {
return (class_id_ ==
reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->class_id_ &&
str_ == reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->str_ &&
dawg_ == reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->dawg_ &&
start_edge_ ==
reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->start_edge_ &&
end_edge_ ==
reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->end_edge_ &&
edge_mask_ ==
reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->edge_mask_);
}
// Creates a set of fan-out edges for the specified edge
static int CreateChildren(CubeRecoContext *cntxt,
const Dawg *edges,
NODE_REF edge_reg,
LangModEdge **lm_edges);
private:
bool root_;
CubeRecoContext *cntxt_;
const Dawg *dawg_;
EDGE_REF start_edge_;
EDGE_REF end_edge_;
EDGE_REF edge_mask_;
int path_cost_;
int class_id_;
const char_32 * str_;
// returns the cost of the lang_mod_edge
inline int Cost() const {
if (cntxt_ != NULL) {
CubeTuningParams *params =
reinterpret_cast<CubeTuningParams *>(cntxt_->Params());
if (dawg_ == (Dawg *)DAWG_OOD) {
return static_cast<int>(params->OODWgt() * MIN_PROB_COST);
} else if (dawg_ == (Dawg *)DAWG_NUMBER) {
return static_cast<int>(params->NumWgt() * MIN_PROB_COST);
}
}
return 0;
}
};
} // namespace tesseract
#endif // TESS_LANG_MOD_EDGE_H