class AliasedBitmapSource : BitmapSource
{
private Bitmap source;
public AliasedBitmapSource(Bitmap source)
{
this.source = source;
this.pixelHeight = source.Height;
this.pixelWidth = source.Width;
this.dpiX = source.HorizontalResolution;
this.dpiY = source.VerticalResolution;
}

public override event EventHandler DownloadCompleted;
public override event EventHandler<ExceptionEventArgs> DownloadFailed;
public override event EventHandler<ExceptionEventArgs> DecodeFailed;

protected override Freezable CreateInstanceCore()
{
throw new NotImplementedException();
}

private readonly double dpiX;
public override double DpiX
{
get
{
return dpiX;
}
}

private readonly double dpiY;
public override double DpiY
{
get
{
return dpiY;
}
}

private readonly int pixelHeight;
public override int PixelHeight
{
get
{
return pixelHeight;
}
}

private readonly int pixelWidth;
public override int PixelWidth
{
get
{
return pixelWidth;
}
}

public override System.Windows.Media.PixelFormat Format
{
get
{
return PixelFormats.Bgra32;
}
}

public override BitmapPalette Palette
{
get
{
return null;
}
}

public unsafe override void CopyPixels(Int32Rect sourceRect, Array pixels, int stride, int offset)
{
BitmapData sourceData = source.LockBits(
sourceRect.ToRectangle(),
ImageLockMode.ReadWrite,
System.Drawing.Imaging.PixelFormat.Format32bppArgb);

fixed (byte* _ptr = &((byte[])pixels)[0])
{
byte* dstptr = _ptr;
byte* srcptr = (byte*)sourceData.Scan0;

for (int i = 0; i < pixels.Length; ++i)
{
*dstptr = *srcptr;
++dstptr;
++srcptr;
}
}

source.UnlockBits(sourceData);
}
}

public static class Extensions
{
public static Rectangle ToRectangle(this Int32Rect me)
{
return new Rectangle(
me.X,
me.Y,
me.Width,
me.Height);
}

public static Int32Rect ToInt32Rect(this Rectangle me)
{
return new Int32Rect(
me.X,
me.Y,
me.Width,
me.Height);
}
}