WPF: Windows 7 like Button Color Hot Tracking

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Data;
using System.Globalization;
using System.Windows.Media.Imaging;
using System.Windows.Media;
using System.Collections;
using System.Drawing;
using System.IO;

namespace ColorHotTrackButton
{
    /// <summary>
    /// Converter writen by Rudi, just modified a bit
    /// </summary>
    public class IconToAvgColorBrushConverter : IValueConverter
    {
        /// <summary>
        /// The converter method
        /// </summary>
        /// <param name="value"></param>
        /// <param name="targetType"></param>
        /// <param name="parameter"></param>
        /// <param name="culture"></param>
        /// <returns></returns>
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            // Verify if the value is null, if it is return a transparent brush
            if (value == null)
            {
                return System.Windows.Media.Brushes.Transparent;
            }

            // Instanciate a MemoryStream to acomodate the bitmap
            MemoryStream stream = new MemoryStream();

            // verify if the value is from the espected Type
            if (value is RenderTargetBitmap)
            {
                // Load the rendered visual element from the render to a BitmapFrame
                BitmapFrame frame = BitmapFrame.Create(value as RenderTargetBitmap);
                // Instanciate the Encoder for the image and add the frame to it
                System.Windows.Media.Imaging.BmpBitmapEncoder e = new BmpBitmapEncoder();
                e.Frames.Add(frame);
                // Save the data to the stream object
                e.Save(stream);
            }

            try
            {
                using (Bitmap bitmap = new Bitmap(stream))
                {
                    // Create an Array to acomodate the colors from the image
                    ArrayList colors = new ArrayList();

                    // simple loop to load each color to the array
                    for (int x = 0; x < bitmap.Width; x++)
                    {
                        for (int y = 0; y < bitmap.Height; y++)
                        {
                            System.Drawing.Color pixel = bitmap.GetPixel(x, y);
                            // verify if the color is transparent because a color of #00000000 would darker the brush
                            if (pixel.A > 0x00)
                                colors.Add(pixel);
                        }
                    }

                    // Using linq to get the average color RGB bytes
                    byte r = (byte)Math.Floor(colors.Cast<System.Drawing.Color>().Average(c => c.R));
                    byte g = (byte)Math.Floor(colors.Cast<System.Drawing.Color>().Average(c => c.G));
                    byte b = (byte)Math.Floor(colors.Cast<System.Drawing.Color>().Average(c => c.B));

                    // Instanciate and initialize the LinearGradientBrush that will be returned as the result of the operation
                    LinearGradientBrush brush = new LinearGradientBrush();
                    brush.EndPoint = new System.Windows.Point(0.5, 1.0);
                    brush.StartPoint = new System.Windows.Point(0.5, 0.0);
                    brush.GradientStops.Add(new GradientStop(System.Windows.Media.Color.FromArgb(0x00, r, g, b), 0.00));
                    brush.GradientStops.Add(new GradientStop(System.Windows.Media.Color.FromArgb(0xFF, r, g, b), 1.00));
                    return brush;
                }
            }
            catch (Exception)
            {
                // If any error occours return a Tranparent brush
                return System.Windows.Media.Brushes.Transparent;
            }
        }

        /// <summary>
        /// Just ignored cause it is not supposed to do anything
        /// </summary>
        /// <param name="value"></param>
        /// <param name="targetType"></param>
        /// <param name="parameter"></param>
        /// <param name="culture"></param>
        /// <returns></returns>
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new Exception("The method or operation is not implemented.");
        }
    }
}