mirror of
https://github.com/tesseract-ocr/tesseract.git
synced 2024-11-24 02:59:07 +08:00
4523ce9f7d
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@526 d0cd1f9f-072b-0410-8dd7-cf729c803f20
95 lines
4.1 KiB
C++
95 lines
4.1 KiB
C++
/**********************************************************************
|
|
* File: conv_net_classifier.h
|
|
* Description: Declaration of Convolutional-NeuralNet Character Classifier
|
|
* Author: Ahmad Abdulkader
|
|
* Created: 2007
|
|
*
|
|
* (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 ConvNetCharClassifier inherits from the base classifier class:
|
|
// "CharClassifierBase". It implements a Convolutional Neural Net classifier
|
|
// instance of the base classifier. It uses the Tesseract Neural Net library
|
|
// The Neural Net takes a scaled version of a bitmap and feeds it to a
|
|
// Convolutional Neural Net as input and performs a FeedForward. Each output
|
|
// of the net corresponds to class_id in the CharSet passed at construction
|
|
// time.
|
|
// Afterwards, the outputs of the Net are "folded" using the folding set
|
|
// (if any)
|
|
#ifndef CONV_NET_CLASSIFIER_H
|
|
#define CONV_NET_CLASSIFIER_H
|
|
|
|
#include <string>
|
|
#include "char_samp.h"
|
|
#include "char_altlist.h"
|
|
#include "char_set.h"
|
|
#include "feature_base.h"
|
|
#include "classifier_base.h"
|
|
#include "neural_net.h"
|
|
#include "lang_model.h"
|
|
#include "tuning_params.h"
|
|
|
|
namespace tesseract {
|
|
|
|
// Folding Ratio is the ratio of the max-activation of members of a folding
|
|
// set that is used to compute the min-activation of the rest of the set
|
|
static const float kFoldingRatio = 0.75;
|
|
|
|
class ConvNetCharClassifier : public CharClassifier {
|
|
public:
|
|
ConvNetCharClassifier(CharSet *char_set, TuningParams *params,
|
|
FeatureBase *feat_extract);
|
|
virtual ~ConvNetCharClassifier();
|
|
// The main training function. Given a sample and a class ID the classifier
|
|
// updates its parameters according to its learning algorithm. This function
|
|
// is currently not implemented. TODO(ahmadab): implement end-2-end training
|
|
virtual bool Train(CharSamp *char_samp, int ClassID);
|
|
// A secondary function needed for training. Allows the trainer to set the
|
|
// value of any train-time paramter. This function is currently not
|
|
// implemented. TODO(ahmadab): implement end-2-end training
|
|
virtual bool SetLearnParam(char *var_name, float val);
|
|
// Externally sets the Neural Net used by the classifier. Used for training
|
|
void SetNet(tesseract::NeuralNet *net);
|
|
|
|
// Classifies an input charsamp and return a CharAltList object containing
|
|
// the possible candidates and corresponding scores
|
|
virtual CharAltList * Classify(CharSamp *char_samp);
|
|
// Computes the cost of a specific charsamp being a character (versus a
|
|
// non-character: part-of-a-character OR more-than-one-character)
|
|
virtual int CharCost(CharSamp *char_samp);
|
|
|
|
|
|
private:
|
|
// Neural Net object used for classification
|
|
tesseract::NeuralNet *char_net_;
|
|
// data buffers used to hold Neural Net inputs and outputs
|
|
float *net_input_;
|
|
float *net_output_;
|
|
|
|
// Init the classifier provided a data-path and a language string
|
|
virtual bool Init(const string &data_file_path, const string &lang,
|
|
LangModel *lang_mod);
|
|
// Loads the NeuralNets needed for the classifier
|
|
bool LoadNets(const string &data_file_path, const string &lang);
|
|
// Loads the folding sets provided a data-path and a language string
|
|
virtual bool LoadFoldingSets(const string &data_file_path,
|
|
const string &lang,
|
|
LangModel *lang_mod);
|
|
// Folds the output of the NeuralNet using the loaded folding sets
|
|
virtual void Fold();
|
|
// Scales the input char_samp and feeds it to the NeuralNet as input
|
|
bool RunNets(CharSamp *char_samp);
|
|
};
|
|
}
|
|
#endif // CONV_NET_CLASSIFIER_H
|