WPF Image Resize code for LINQPad

ResizeWPF.linq

<Query Kind="Statements">
  <Reference>&lt;RuntimeDirectory&gt;\System.Xaml.dll</Reference>
  <Reference>&lt;RuntimeDirectory&gt;\WPF\WindowsBase.dll</Reference>
  <Reference>&lt;RuntimeDirectory&gt;\WPF\PresentationCore.dll</Reference>
  <Namespace>System.Windows.Media</Namespace>
  <Namespace>System.Windows.Media.Imaging</Namespace>
</Query>

var ThumbnailSize = 800;
var source = @"C:\Users\Heather\Pictures\Canon SX230";
var dest = @"C:\Users\Heather\Desktop\SX230";

if (!Directory.Exists(dest)) { Directory.CreateDirectory(dest); }

foreach (var file in Directory.GetFiles(source, "*.jpg", SearchOption.AllDirectories))
{
	using (var s = new MemoryStream(File.ReadAllBytes(file)))
	{
		var decoder = BitmapDecoder.Create(s, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.None);
		var photo = decoder.Frames[0];
		int width, height;
		if (photo.Width > photo.Height)
		{
			width = ThumbnailSize;
			height = (int)(photo.Height * ThumbnailSize / photo.Width);
		}
		else
		{
			width = (int)(photo.Width * ThumbnailSize / photo.Height);
			height = ThumbnailSize;
		}
		var target = new TransformedBitmap(photo, new ScaleTransform(
			width / photo.Width * 96 / photo.DpiX,
			height / photo.Height * 96 / photo.DpiY,
			0, 0));
			
		var final = BitmapFrame.Create(target);
		var encoder = new JpegBitmapEncoder { QualityLevel = 90 };
		encoder.Frames.Add(final);
		var d = Path.Combine(dest, Path.GetFileName(file));
		using (var f = File.Create(d))
		{
			encoder.Save(f);
		}
	}
}