Neural Network OCR

// AForge Math Library
//
// Copyright � Andrew Kirillov, 2005
// andrew.kirillov@gmail.com
//

namespace AForge.Math
{
	using System;

	/// <summary>
	/// Tools
	/// </summary>
	public class Tools
	{
		// Calculate the power of 2, exp: [0, 30]
		public static int Pow2(int exp)
		{
			return ((exp >= 0) && (exp <= 30)) ? (1 << exp) : 0;
		}

		// Check if the integer is a power of 2
		public static bool IsPowerOf2(int x) 
		{
			return (x & (x - 1)) == 0;
		}

		// Get base of 2 logarithm
		public static int Log2(int x)
		{
			if (x <= 65536)
			{
				if (x <= 256)
				{
					if (x <= 16)
					{
						if (x <= 4)
						{
							if (x <= 2)
							{
								if (x <= 1)
									return 0;
								return 1;
							}
							return 2;
						}
						if (x <= 8)
							return 3;
						return 4;
					}
					if (x <= 64)
					{
						if (x <= 32)
							return 5;
						return 6;
					}
					if (x <= 128)
						return 7;
					return 8;
				}
				if (x <= 4096)
				{
					if (x <= 1024)
					{
						if (x <= 512)
							return 9;
						return 10;
					}
					if (x <= 2048)
						return 11;
					return 12;
				}
				if (x <= 16384)
				{
					if (x <= 8192)
						return 13;
					return 14;
				}
				if (x <= 32768)
					return 15;
				return 16;
			}

			if (x <= 16777216)
			{
				if (x <= 1048576)
				{
					if (x <= 262144)
					{
						if (x <= 131072)
							return 17;
						return 18;
					}
					if (x <= 524288)
						return 19;
					return 20;
				}
				if (x <= 4194304) 
				{
					if (x <= 2097152)
						return 21;
					return 22;
				}
				if (x <= 8388608)
					return 23;
				return 24;
			}
			if (x <= 268435456)
			{
				if (x <= 67108864)
				{
					if (x <= 33554432)
						return 25;
					return 26;
				}
				if (x <= 134217728)
					return 27;
				return 28;
			}
			if (x <= 1073741824)
			{
				if (x <= 536870912)
					return 29;
				return 30;
			}
			return 31;
		}
	}
}