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58 lines
2.2 KiB
C
58 lines
2.2 KiB
C
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/**********************************************************************
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* File: feature_chebyshev.h
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* Description: Declaration of the Chebyshev coefficients Feature Class
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* Author: Ahmad Abdulkader
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* Created: 2008
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*
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* (C) Copyright 2008, Google Inc.
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** Licensed under the Apache License, Version 2.0 (the "License");
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** you may not use this file except in compliance with the License.
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** You may obtain a copy of the License at
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** http://www.apache.org/licenses/LICENSE-2.0
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** Unless required by applicable law or agreed to in writing, software
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** distributed under the License is distributed on an "AS IS" BASIS,
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** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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** See the License for the specific language governing permissions and
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** limitations under the License.
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*
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**********************************************************************/
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// The FeatureChebyshev class implements a Bitmap feature extractor class. It
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// inherits from the FeatureBase class
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// The feature vector is the composed of the chebyshev coefficients of 4 time
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// sequences. The time sequences are the left, top, right & bottom
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// bitmap profiles of the input samples
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#ifndef FEATURE_CHEBYSHEV_H
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#define FEATURE_CHEBYSHEV_H
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#include "char_samp.h"
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#include "feature_base.h"
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namespace tesseract {
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class FeatureChebyshev : public FeatureBase {
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public:
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explicit FeatureChebyshev(TuningParams *params);
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virtual ~FeatureChebyshev();
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// Render a visualization of the features to a CharSamp.
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// This is mainly used by visual-debuggers
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virtual CharSamp *ComputeFeatureBitmap(CharSamp *samp);
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// Compute the features for a given CharSamp
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virtual bool ComputeFeatures(CharSamp *samp, float *features);
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// Returns the count of features
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virtual int FeatureCnt() {
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return (4 * kChebychevCoefficientCnt);
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}
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protected:
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static const int kChebychevCoefficientCnt = 40;
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// Compute Chebychev coefficients for the specified vector
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void ChebyshevCoefficients(const vector<float> &input,
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int coeff_cnt, float *coeff);
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// Compute the features for a given CharSamp
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bool ComputeChebyshevCoefficients(CharSamp *samp, float *features);
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};
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}
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#endif // FEATURE_CHEBYSHEV_H
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