tesseract/classify/ocrfeatures.h
2015-05-12 18:13:15 -07:00

126 lines
4.9 KiB
C++

/******************************************************************************
** Filename: features.h
** Purpose: Generic definition of a feature.
** Author: Dan Johnson
** History: Sun May 20 10:28:30 1990, DSJ, Created.
**
** (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 FEATURES_H
#define FEATURES_H
/**----------------------------------------------------------------------------
Include Files and Type Defines
----------------------------------------------------------------------------**/
#include "blobs.h"
#include <stdio.h>
class DENORM;
struct INT_FX_RESULT_STRUCT;
#undef Min
#undef Max
#define FEAT_NAME_SIZE 80
// define trap errors which can be caused by this module
#define ILLEGAL_FEATURE_PARAM 1000
#define ILLEGAL_NUM_FEATURES 1001
// A character is described by multiple sets of extracted features. Each
// set contains a number of features of a particular type, for example, a
// set of bays, or a set of closures, or a set of microfeatures. Each
// feature consists of a number of parameters. All features within a
// feature set contain the same number of parameters. All circular
// parameters are required to be the first parameters in the feature.
struct PARAM_DESC {
inT8 Circular; // TRUE if dimension wraps around
inT8 NonEssential; // TRUE if dimension not used in searches
FLOAT32 Min; // low end of range for circular dimensions
FLOAT32 Max; // high end of range for circular dimensions
FLOAT32 Range; // Max - Min
FLOAT32 HalfRange; // (Max - Min)/2
FLOAT32 MidRange; // (Max + Min)/2
};
struct FEATURE_DESC_STRUCT {
uinT16 NumParams; // total # of params
const char *ShortName; // short name for feature
const PARAM_DESC *ParamDesc; // array - one per param
};
typedef FEATURE_DESC_STRUCT *FEATURE_DESC;
struct FEATURE_STRUCT {
const FEATURE_DESC_STRUCT *Type; // points to description of feature type
FLOAT32 Params[1]; // variable size array - params for feature
};
typedef FEATURE_STRUCT *FEATURE;
struct FEATURE_SET_STRUCT {
uinT16 NumFeatures; // number of features in set
uinT16 MaxNumFeatures; // maximum size of feature set
FEATURE Features[1]; // variable size array of features
};
typedef FEATURE_SET_STRUCT *FEATURE_SET;
// A generic character description as a char pointer. In reality, it will be
// a pointer to some data structure. Paired feature extractors/matchers need
// to agree on the data structure to be used, however, the high level
// classifier does not need to know the details of this data structure.
typedef char *CHAR_FEATURES;
/*----------------------------------------------------------------------
Macros for defining the parameters of a new features
----------------------------------------------------------------------*/
#define StartParamDesc(Name) \
const PARAM_DESC Name[] = {
#define DefineParam(Circular, NonEssential, Min, Max) \
{Circular, NonEssential, Min, Max, \
(Max) - (Min), (((Max) - (Min))/2.0), (((Max) + (Min))/2.0)},
#define EndParamDesc };
/*----------------------------------------------------------------------
Macro for describing a new feature. The parameters of the macro
are as follows:
DefineFeature (Name, NumLinear, NumCircular, ShortName, ParamName)
----------------------------------------------------------------------*/
#define DefineFeature(Name, NL, NC, SN, PN) \
const FEATURE_DESC_STRUCT Name = { \
((NL) + (NC)), SN, PN};
/*----------------------------------------------------------------------
Generic routines that work for all feature types
----------------------------------------------------------------------*/
BOOL8 AddFeature(FEATURE_SET FeatureSet, FEATURE Feature);
void FreeFeature(FEATURE Feature);
void FreeFeatureSet(FEATURE_SET FeatureSet);
FEATURE NewFeature(const FEATURE_DESC_STRUCT *FeatureDesc);
FEATURE_SET NewFeatureSet(int NumFeatures);
FEATURE ReadFeature(FILE *File, const FEATURE_DESC_STRUCT *FeatureDesc);
FEATURE_SET ReadFeatureSet(FILE *File, const FEATURE_DESC_STRUCT *FeatureDesc);
void WriteFeature(FEATURE Feature, STRING* str);
void WriteFeatureSet(FEATURE_SET FeatureSet, STRING* str);
#endif