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tess_lang_mod_edge.h
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1 /**********************************************************************
2 * File: tess_lang_mod_edge.h
3 * Description: Declaration of the Tesseract Language Model Edge Class
4 * Author: Ahmad Abdulkader
5 * Created: 2008
6 *
7 * (C) Copyright 2008, Google Inc.
8 ** Licensed under the Apache License, Version 2.0 (the "License");
9 ** you may not use this file except in compliance with the License.
10 ** You may obtain a copy of the License at
11 ** http://www.apache.org/licenses/LICENSE-2.0
12 ** Unless required by applicable law or agreed to in writing, software
13 ** distributed under the License is distributed on an "AS IS" BASIS,
14 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 ** See the License for the specific language governing permissions and
16 ** limitations under the License.
17 *
18 **********************************************************************/
19
20 // The TessLangModEdge models an edge in the Tesseract language models
21 // It inherits from the LangModEdge class
22
23 #ifndef TESS_LANG_MOD_EDGE_H
24 #define TESS_LANG_MOD_EDGE_H
25
26 #include "dawg.h"
27 #include "char_set.h"
28
29 #include "lang_mod_edge.h"
30 #include "cube_reco_context.h"
31 #include "cube_utils.h"
32
33 // Macros needed to identify punctuation in the langmodel state
34 #ifdef _HMSW32_H
35 #define LEAD_PUNC_EDGE_REF_MASK (inT64) 0x0000000100000000i64
36 #define TRAIL_PUNC_EDGE_REF_MASK (inT64) 0x0000000200000000i64
37 #define TRAIL_PUNC_REPEAT_MASK (inT64) 0xffff000000000000i64
38 #else
39 #define LEAD_PUNC_EDGE_REF_MASK (inT64) 0x0000000100000000ll
40 #define TRAIL_PUNC_EDGE_REF_MASK (inT64) 0x0000000200000000ll
41 #define TRAIL_PUNC_REPEAT_MASK (inT64) 0xffff000000000000ll
42 #endif
43
44 // Number state machine macros
45 #define NUMBER_STATE_SHIFT 0
46 #define NUMBER_STATE_MASK 0x0000000fl
47 #define NUMBER_LITERAL_SHIFT 4
48 #define NUMBER_LITERAL_MASK 0x000000f0l
49 #define NUMBER_REPEAT_SHIFT 8
50 #define NUMBER_REPEAT_MASK 0x00000f00l
51 #define NUM_TRM -99
52 #define TRAIL_PUNC_REPEAT_SHIFT 48
53
54 #define IsLeadingPuncEdge(edge_mask) \
55 ((edge_mask & LEAD_PUNC_EDGE_REF_MASK) != 0)
56 #define IsTrailingPuncEdge(edge_mask) \
57 ((edge_mask & TRAIL_PUNC_EDGE_REF_MASK) != 0)
58 #define TrailingPuncCount(edge_mask) \
59 ((edge_mask & TRAIL_PUNC_REPEAT_MASK) >> TRAIL_PUNC_REPEAT_SHIFT)
60 #define TrailingPuncEdgeMask(Cnt) \
61 (TRAIL_PUNC_EDGE_REF_MASK | ((Cnt) << TRAIL_PUNC_REPEAT_SHIFT))
62
63 // State machine IDs
64 #define DAWG_OOD 0
65 #define DAWG_NUMBER 1
66
67 namespace tesseract {
68 class TessLangModEdge : public LangModEdge {
69 public:
70 // Different ways of constructing a TessLangModEdge
71 TessLangModEdge(CubeRecoContext *cntxt, const Dawg *edge_array,
72 EDGE_REF edge, int class_id);
73 TessLangModEdge(CubeRecoContext *cntxt, const Dawg *edge_array,
74 EDGE_REF start_edge_idx, EDGE_REF end_edge_idx,
75 int class_id);
76 TessLangModEdge(CubeRecoContext *cntxt, int class_id);
77 ~TessLangModEdge() {}
78
79 // Accessors
80 inline bool IsRoot() const {
81 return root_;
82 }
83 inline void SetRoot(bool flag) { root_ = flag; }
84
85 inline bool IsOOD() const {
86 return (dawg_ == (Dawg *)DAWG_OOD);
87 }
88
89 inline bool IsNumber() const {
90 return (dawg_ == (Dawg *)DAWG_NUMBER);
91 }
92
93 inline bool IsEOW() const {
94 return (IsTerminal() || (dawg_->end_of_word(end_edge_) != 0));
95 }
96
97 inline const Dawg *GetDawg() const { return dawg_; }
98 inline EDGE_REF StartEdge() const { return start_edge_; }
99 inline EDGE_REF EndEdge() const { return end_edge_; }
100 inline EDGE_REF EdgeMask() const { return edge_mask_; }
101 inline const char_32 * EdgeString() const { return str_; }
102 inline int ClassID () const { return class_id_; }
103 inline int PathCost() const { return path_cost_; }
104 inline void SetEdgeMask(EDGE_REF edge_mask) { edge_mask_ = edge_mask; }
105 inline void SetDawg(Dawg *dawg) { dawg_ = dawg; }
106 inline void SetStartEdge(EDGE_REF edge_idx) { start_edge_ = edge_idx; }
107 inline void SetEndEdge(EDGE_REF edge_idx) { end_edge_ = edge_idx; }
108
109 // is this a terminal node:
110 // we can terminate at any OOD char, trailing punc or
111 // when the dawg terminates
112 inline bool IsTerminal() const {
113 return (IsOOD() || IsNumber() || IsTrailingPuncEdge(start_edge_) ||
114 dawg_->next_node(end_edge_) == 0);
115 }
116
117 // How many signals does the LM provide for tuning. These are flags like:
118 // OOD or not, Number of not that are used by the training to compute
119 // extra costs for each word.
120 inline int SignalCnt() const {
121 return 2;
122 }
123
124 // returns the weight assigned to a specified signal
125 inline double SignalWgt(int signal) const {
126 CubeTuningParams *params =
127 reinterpret_cast<CubeTuningParams *>(cntxt_->Params());
128 if (params != NULL) {
129 switch (signal) {
130 case 0:
131 return params->OODWgt();
132 break;
133
134 case 1:
135 return params->NumWgt();
136 break;
137 }
138 }
139
140 return 0.0;
141 }
142
143 // sets the weight assigned to a specified signal: Used in training
144 void SetSignalWgt(int signal, double wgt) {
145 CubeTuningParams *params =
146 reinterpret_cast<CubeTuningParams *>(cntxt_->Params());
147 if (params != NULL) {
148 switch (signal) {
149 case 0:
150 params->SetOODWgt(wgt);
151 break;
152
153 case 1:
154 params->SetNumWgt(wgt);
155 break;
156 }
157 }
158 }
159
160 // returns the actual value of a specified signal
161 int Signal(int signal) {
162 switch (signal) {
163 case 0:
164 return IsOOD() ? MIN_PROB_COST : 0;
165 break;
166
167 case 1:
168 return IsNumber() ? MIN_PROB_COST : 0;
169 break;
170
171 default:
172 return 0;
173 }
174 }
175
176 // returns the Hash value of the edge. Used by the SearchNode hash table
177 // to quickly lookup exisiting edges to converge during search
178 inline unsigned int Hash() const {
179 return static_cast<unsigned int>(((start_edge_ | end_edge_) ^
180 ((reinterpret_cast<unsigned long int>(dawg_)))) ^
181 ((unsigned int)edge_mask_) ^
182 class_id_);
183 }
184
185 // A verbal description of the edge: Used by visualizers
186 char *Description() const;
187
188 // Is this edge identical to the specified edge
189 inline bool IsIdentical(LangModEdge *lang_mod_edge) const {
190 return (class_id_ ==
191 reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->class_id_ &&
192 str_ == reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->str_ &&
193 dawg_ == reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->dawg_ &&
194 start_edge_ ==
195 reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->start_edge_ &&
196 end_edge_ ==
197 reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->end_edge_ &&
198 edge_mask_ ==
199 reinterpret_cast<TessLangModEdge *>(lang_mod_edge)->edge_mask_);
200 }
201
202 // Creates a set of fan-out edges for the specified edge
203 static int CreateChildren(CubeRecoContext *cntxt,
204 const Dawg *edges,
205 NODE_REF edge_reg,
206 LangModEdge **lm_edges);
207
208 private:
209 bool root_;
210 CubeRecoContext *cntxt_;
211 const Dawg *dawg_;
212 EDGE_REF start_edge_;
213 EDGE_REF end_edge_;
214 EDGE_REF edge_mask_;
215 int path_cost_;
216 int class_id_;
217 const char_32 * str_;
218 // returns the cost of the lang_mod_edge
219 inline int Cost() const {
220 if (cntxt_ != NULL) {
221 CubeTuningParams *params =
222 reinterpret_cast<CubeTuningParams *>(cntxt_->Params());
223 if (dawg_ == (Dawg *)DAWG_OOD) {
224 return static_cast<int>(params->OODWgt() * MIN_PROB_COST);
225 } else if (dawg_ == (Dawg *)DAWG_NUMBER) {
226 return static_cast<int>(params->NumWgt() * MIN_PROB_COST);
227 }
228 }
229 return 0;
230 }
231 };
232 } // namespace tesseract
233
234 #endif // TESS_LANG_MOD_EDGE_H