tesseract/cube/feature_chebyshev.h

58 lines
2.2 KiB
C++

/**********************************************************************
* File: feature_chebyshev.h
* Description: Declaration of the Chebyshev coefficients Feature 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 FeatureChebyshev class implements a Bitmap feature extractor class. It
// inherits from the FeatureBase class
// The feature vector is the composed of the chebyshev coefficients of 4 time
// sequences. The time sequences are the left, top, right & bottom
// bitmap profiles of the input samples
#ifndef FEATURE_CHEBYSHEV_H
#define FEATURE_CHEBYSHEV_H
#include "char_samp.h"
#include "feature_base.h"
namespace tesseract {
class FeatureChebyshev : public FeatureBase {
public:
explicit FeatureChebyshev(TuningParams *params);
virtual ~FeatureChebyshev();
// Render a visualization of the features to a CharSamp.
// This is mainly used by visual-debuggers
virtual CharSamp *ComputeFeatureBitmap(CharSamp *samp);
// Compute the features for a given CharSamp
virtual bool ComputeFeatures(CharSamp *samp, float *features);
// Returns the count of features
virtual int FeatureCnt() {
return (4 * kChebychevCoefficientCnt);
}
protected:
static const int kChebychevCoefficientCnt = 40;
// Compute Chebychev coefficients for the specified vector
void ChebyshevCoefficients(const vector<float> &input,
int coeff_cnt, float *coeff);
// Compute the features for a given CharSamp
bool ComputeChebyshevCoefficients(CharSamp *samp, float *features);
};
}
#endif // FEATURE_CHEBYSHEV_H