intmatcher.h

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/******************************************************************************
 ** Filename:    intmatcher.h
 ** Purpose:     Interface to high level generic classifier routines.
 ** Author:      Robert Moss
 **
 ** (c) Copyright Hewlett-Packard Company, 1988.
 ** 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 INTMATCHER_H
#define INTMATCHER_H
 
#include "intproto.h"
#include "params.h"
 
namespace tesseract {
 
// Character fragments could be present in the trained templaes
// but turned on/off on the language-by-language basis or depending
// on particular properties of the corpus (e.g. when we expect the
// images to have low exposure).
extern BOOL_VAR_H(disable_character_fragments);
 
extern INT_VAR_H(classify_integer_matcher_multiplier);
 
struct UnicharRating;
 
struct CP_RESULT_STRUCT {
  CP_RESULT_STRUCT() : Rating(0.0f), Class(0) {}
 
  float Rating;
  CLASS_ID Class;
};
 
#define SE_TABLE_BITS 9
#define SE_TABLE_SIZE 512
 
struct ScratchEvidence {
  uint8_t feature_evidence_[MAX_NUM_CONFIGS];
  int sum_feature_evidence_[MAX_NUM_CONFIGS];
  uint8_t proto_evidence_[MAX_NUM_PROTOS][MAX_PROTO_INDEX];
 
  void Clear(const INT_CLASS_STRUCT *class_template);
  void ClearFeatureEvidence(const INT_CLASS_STRUCT *class_template);
  void NormalizeSums(INT_CLASS_STRUCT *ClassTemplate, int16_t NumFeatures);
  void UpdateSumOfProtoEvidences(INT_CLASS_STRUCT *ClassTemplate, BIT_VECTOR ConfigMask);
};
 
class IntegerMatcher {
public:
  // Integer Matcher Theta Fudge (0-255).
  static const int kIntThetaFudge = 128;
  // Bits in Similarity to Evidence Lookup (8-9).
  static const int kEvidenceTableBits = 9;
  // Integer Evidence Truncation Bits (8-14).
  static const int kIntEvidenceTruncBits = 14;
  // Similarity to Evidence Table Exponential Multiplier.
  static const float kSEExponentialMultiplier;
  // Center of Similarity Curve.
  static const float kSimilarityCenter;
 
  IntegerMatcher(tesseract::IntParam *classify_debug_level);
 
  void Match(INT_CLASS_STRUCT *ClassTemplate, BIT_VECTOR ProtoMask, BIT_VECTOR ConfigMask,
             int16_t NumFeatures, const INT_FEATURE_STRUCT *Features,
             tesseract::UnicharRating *Result, int AdaptFeatureThreshold, int Debug,
             bool SeparateDebugWindows);
 
  // Applies the CN normalization factor to the given rating and returns
  // the modified rating.
  float ApplyCNCorrection(float rating, int blob_length, int normalization_factor,
                          int matcher_multiplier);
 
  int FindGoodProtos(INT_CLASS_STRUCT *ClassTemplate, BIT_VECTOR ProtoMask, BIT_VECTOR ConfigMask,
                     int16_t NumFeatures, INT_FEATURE_ARRAY Features, PROTO_ID *ProtoArray,
                     int AdaptProtoThreshold, int Debug);
 
  int FindBadFeatures(INT_CLASS_STRUCT *ClassTemplate, BIT_VECTOR ProtoMask, BIT_VECTOR ConfigMask,
                      int16_t NumFeatures, INT_FEATURE_ARRAY Features, FEATURE_ID *FeatureArray,
                      int AdaptFeatureThreshold, int Debug);
 
private:
  int UpdateTablesForFeature(INT_CLASS_STRUCT *ClassTemplate, BIT_VECTOR ProtoMask, BIT_VECTOR ConfigMask,
                             int FeatureNum, const INT_FEATURE_STRUCT *Feature,
                             ScratchEvidence *evidence, int Debug);
 
  int FindBestMatch(INT_CLASS_STRUCT *ClassTemplate, const ScratchEvidence &tables,
                    tesseract::UnicharRating *Result);
 
#ifndef GRAPHICS_DISABLED
  void DebugFeatureProtoError(INT_CLASS_STRUCT *ClassTemplate, BIT_VECTOR ProtoMask, BIT_VECTOR ConfigMask,
                              const ScratchEvidence &tables, int16_t NumFeatures, int Debug);
 
  void DisplayProtoDebugInfo(INT_CLASS_STRUCT *ClassTemplate, BIT_VECTOR ConfigMask,
                             const ScratchEvidence &tables, bool SeparateDebugWindows);
 
  void DisplayFeatureDebugInfo(INT_CLASS_STRUCT *ClassTemplate, BIT_VECTOR ProtoMask, BIT_VECTOR ConfigMask,
                               int16_t NumFeatures, const INT_FEATURE_STRUCT *Features,
                               int AdaptFeatureThreshold, int Debug, bool SeparateDebugWindows);
#endif
 
private:
  tesseract::IntParam *classify_debug_level_;
  uint8_t similarity_evidence_table_[SE_TABLE_SIZE];
  uint32_t evidence_table_mask_;
  uint32_t mult_trunc_shift_bits_;
  uint32_t table_trunc_shift_bits_;
  uint32_t evidence_mult_mask_;
};
 
} // namespace tesseract
 
#endif