using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Drawing.Drawing2D;

namespace SuperTiff
{
	class Program
	{
		static void Main(string[] args)
		{
			if (args.Length < 2)
			{
				Console.WriteLine("Usage: SuperTiff <input> <output>\n\n");
				return;
			}

			// Load the bitmap from first argument filename
			Bitmap bmIn = new Bitmap(args[0]);

			// Create a new bitmap from the first, scaling down as we go
			Bitmap bmOut = new Bitmap(bmIn, new Size(bmIn.Width/2, bmIn.Height/2));

			// Create an parameter set that we use to save the file
			EncoderParameters encParams = new EncoderParameters(3);

			// Set some parameters
 			encParams.Param[0] = new EncoderParameter(Encoder.ColorDepth, 24L);
			encParams.Param[1] = new EncoderParameter(Encoder.Compression, (long)EncoderValue.CompressionNone);
			encParams.Param[2] = new EncoderParameter(Encoder.SaveFlag, (long)EncoderValue.MultiFrame);

			// Convert the pixels from colour to grayscale (note this is *NOT* changing the colour depth)
			Bitmap bmOut2 = ToGrayscale(bmOut);

			// Save bitmap to second argument filename
			bmOut2.Save(args[1], GetEncoder(ImageFormat.Tiff), encParams);
		}


		/// <summary>
		/// Convert bitmap to greyscale
		/// </summary>
		/// <param name="bmIn"></param>
		/// <returns></returns>
		private static Bitmap ToGrayscale(Bitmap bmIn)
		{
			Bitmap bmOut = new Bitmap(bmIn.Width, bmIn.Height, PixelFormat.Format24bppRgb);

			for (int x = 0; x < bmIn.Width; x++)
			{
				for (int y = 0; y < bmIn.Height; y++)
				{
					Color px = bmIn.GetPixel(x, y);

					int luminance = (int)((0.3f * px.R) + (0.59 * px.G) + (0.11 * px.B));

					bmOut.SetPixel(x, y, Color.FromArgb(luminance, luminance, luminance));
				}
			}

			return bmOut;
		}

		/// <summary>
		/// Get the codec for a specific format
		/// </summary>
		/// <param name="format"></param>
		/// <returns></returns>
		private static ImageCodecInfo GetEncoder(ImageFormat format)
		{
			ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();

			foreach (ImageCodecInfo codec in codecs)
			{
				if (codec.FormatID == format.Guid)
				{
					return codec;
				}
			}
			return null;
		}

	}
}