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# Neural Network OCR

, 11 Aug 2005 GPL3
Some ideas about optical character recognition using neural networks.
 AForge.Imaging.dll AForge.Math.dll AForge.NeuralNet.dll NeuroOCR.exe SourceGrid2.dll SourceLibrary.dll AForge Math Math.csproj.user NeuralNet Learning NeuralNet.csproj.user NeuroOCR App.ico NeuroOCR.csproj.user References AForge.Imaging.dll SourceGrid2.dll SourceLibrary.dll ```// AForge Neural Net Library // // Copyright � Andrew Kirillov, 2005 // andrew.kirillov@gmail.com // namespace AForge.NeuralNet { using System; /// /// ActivationFunction interface /// public interface IActivationFunction { // Calculate function value float Output(float input); // Calculate differential of the function value float OutputPrime(float input); // Calculate differential of the function value // using function value as input float OutputPrime2(float input); } // Sigmoid activation function // // 1 // f(x) = ------------------ // 1 + exp(-alfa * x) // // Outpur range: [0, 1] // public class SigmoidFunction : IActivationFunction { private float alfa = 2; // Alfa property public float Alfa { get { return alfa; } set { alfa = value; } } // Constructors public SigmoidFunction() { } public SigmoidFunction(float alfa) { this.alfa = alfa; } // Calculate function value public float Output(float x) { return (float) (1 / (1 + Math.Exp(-alfa * x))); } // Calculate differential of the function value public float OutputPrime(float x) { float y = Output(x); return (float) (alfa * y * (1 - y)); } // Calculate differential of the function value // using function value as input public float OutputPrime2(float y) { return (float) (alfa * y * (1 - y)); } } // Bipolar Sigmoid activation function // // 1 // f(x) = ------------------ - 0.5 // 1 + exp(-alfa * x) // // Outpur range: [-0.5, 0.5] // public class BipolarSigmoidFunction : IActivationFunction { private float alfa = 2; // Alfa property public float Alfa { get { return alfa; } set { alfa = value; } } // Constructors public BipolarSigmoidFunction() { } public BipolarSigmoidFunction(float alfa) { this.alfa = alfa; } // Calculate function value public float Output(float x) { return (float) ((1 / (1 + Math.Exp(-alfa * x))) - 0.5); } // Calculate differential of the function value public float OutputPrime(float x) { float y = Output(x); return (float) (alfa * (0.25 - y * y)); } // Calculate differential of the function value // using function value as input public float OutputPrime2(float y) { return (float) (alfa * (0.25 - y * y)); } } // Hyperbolic Tangens activation function // // exp(alfa * x) - exp(-alfa * x) // f(x) = tanh(alfa * x) = ------------------------------ // exp(alfa * x) + exp(-alfa * x) // // Outpur range: [-1, 1] // public class HyperbolicTangensFunction : IActivationFunction { private float alfa = 1; // Alfa property public float Alfa { get { return alfa; } set { alfa = value; } } // Constructors public HyperbolicTangensFunction() { } public HyperbolicTangensFunction(float alfa) { // dividing alfa by two gives us the same function // as sigmoid function this.alfa = alfa; } // Calculate function value public float Output(float x) { return (float) (Math.Tanh(alfa * x)); } // Calculate differential of the function value public float OutputPrime(float x) { float y = Output(x); return (float) (alfa * (1 - y * y)); } // Calculate differential of the function value // using function value as input public float OutputPrime2(float y) { return (float) (alfa * (1 - y * y)); } } } ```

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 Software Developer IBM United Kingdom
Started software development at about 15 years old and it seems like now it lasts most part of my life. Fortunately did not spend too much time with Z80 and BK0010 and switched to 8086 and further. Similar with programming languages – luckily managed to get away from BASIC and Pascal to things like Assembler, C, C++ and then C#. Apart from daily programming for food, do it also for hobby, where mostly enjoy areas like Computer Vision, Robotics and AI. This led to some open source stuff like AForge.NET and not so open Computer Vision Sandbox.

Going out of computers I am just a man loving his family, enjoying traveling, a bit of books, a bit of movies and a mixture of everything else. Always wanted to learn playing guitar, but it seems like 6 strings are much harder than few dozens of keyboard’s keys. Will keep progressing ...

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