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Image Recognition with Neural Networks

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30 Oct 2007CPOL4 min read 952.5K   46.2K   286  
This article contains a brief description of BackPropagation Artificial Neural Network and its implementation for Image Recognition
#region Copyright (c), Some Rights Reserved
/*##########################################################################
 * 
 * NeuralNetwork.cs
 * -------------------------------------------------------------------------
 * By
 * Murat FIRAT, September 2007
 * 
 * -------------------------------------------------------------------------
 * Description:
 * Contains Neural Network Class(BP1layer,BP2layer or BP3layer) And
 * Callback To Handle Training Process
 * 
 * -------------------------------------------------------------------------
 ###########################################################################*/
#endregion

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;

namespace BPSimplified.Lib
{    
    class NeuralNetwork<T>
        where T : IComparable<T>
    {
        private IBackPropagation<T> NeuralNet;
        private double maximumError = 1.0;
        private int maximumIteration = 10000;
        Dictionary<T, double[]> TrainingSet;

        public delegate void IterationChangedCallBack(object o, NeuralEventArgs args);
        public event IterationChangedCallBack IterationChanged = null;

        public NeuralNetwork(IBackPropagation<T> IBackPro, Dictionary<T, double[]> trainingSet)
        {
            NeuralNet = IBackPro;
            TrainingSet = trainingSet;
            NeuralNet.InitializeNetwork(TrainingSet);
        }

        public bool Train()
        {
            double currentError = 0;
            int currentIteration = 0;
            NeuralEventArgs Args = new NeuralEventArgs() ;

            do
            {
                currentError = 0;
                foreach (KeyValuePair<T, double[]> p in TrainingSet)
                {
                    NeuralNet.ForwardPropagate(p.Value, p.Key);
                    NeuralNet.BackPropagate();
                    currentError += NeuralNet.GetError();
                }
                
                currentIteration++;

                if (IterationChanged != null && currentIteration % 5 == 0)
                {
                    Args.CurrentError = currentError;
                    Args.CurrentIteration = currentIteration;
                    IterationChanged(this, Args);
                }

            } while (currentError > maximumError && currentIteration < maximumIteration && !Args.Stop);
                        
            if (IterationChanged != null)
            {
                Args.CurrentError = currentError;
                Args.CurrentIteration = currentIteration;
                IterationChanged(this, Args);
            }

            if (currentIteration >= maximumIteration || Args.Stop)   
                return false;//Training Not Successful
            
            return true;
        }

        public void Recognize(double[] Input, ref T MatchedHigh, ref double OutputValueHight,
            ref T MatchedLow, ref double OutputValueLow)
        {
            NeuralNet.Recognize(Input, ref MatchedHigh,ref OutputValueHight,ref MatchedLow,ref OutputValueLow);
        }

        public void SaveNetwork(string path)
        {
            FileStream FS = new FileStream(path, FileMode.Create);
            BinaryFormatter BF = new BinaryFormatter();
            BF.Serialize(FS, NeuralNet);
            FS.Close();
        }

        public void LoadNetwork(string path)
        {
            FileStream FS = new FileStream(path, FileMode.Open);
            BinaryFormatter BF = new BinaryFormatter();
            NeuralNet = (IBackPropagation<T>)BF.Deserialize(FS);
            FS.Close();
        }

        public double MaximumError
        {
            get { return maximumError; }
            set { maximumError = value; }
        }

        public int MaximumIteration
        {
            get { return maximumIteration; }
            set { maximumIteration = value; }
        }
    }
}

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License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer (Senior)
Turkey Turkey
Has BS degree on computer science, working as software engineer in istanbul.

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