ASP.NET MVC ImageHandler for thumbnails

As some of you might know, I am a really big fan of community-driven technologies. I also like to contribute myself in order to exchange new ideas and meet new people with common interests.Since I am quite new to ASP.NET MVC, I was thinking I would submit my first contribution : handling all your images through a custom actionresult/controller.
This allows me to do several things :

uniform access to images
possibility for custom types (this example ALWAYs renders as PNG)
generation of thumbnails.

Let's start with the code for the ActionResult (initially inspired by/copy-pasted from this , but since the new RC it is my own code):

using System.IO;
using System.Web.Mvc;
using System.Drawing;
using System.Drawing.Imaging;

namespace Be.Corebvba.MVC
{
public class ImageResult : FileStreamResult
{
public ImageResult(Image input):this(input,input.Width,input.Height) { }

    public ImageResult(Image input, int width,int height) :
       base(
         GetMemoryStream(input,width,height,ImageFormat.Png),
         "image/png")
   { }

    static MemoryStream GetMemoryStream(Image input,int width,int height,ImageFormat fmt)
    {
       // maintain aspect ratio
       if (input.Width > input.Height)
          height = input.Height * width / input.Width;
       else
          width = input.Width * height / input.Height;

       var bmp = new Bitmap(input, width, height);
       var ms = new MemoryStream();
       bmp.Save(ms, ImageFormat.Png);
       ms.Position = 0;
       return ms;
     }
   }
}

The code for the controller is pretty straighforward as well :

public ActionResult ThumbImage(int id,int width,int height)
{
   var d = _rDocument.GetById(id);
   Image i=null;
   try
   {
      i = Image.FromFile(d.PhysicalFilename);
      return new Be.Corebvba.MVC.ImageResult(i, width, height);
   }
   catch (Exception ex)
   {
      i = new Bitmap(1, 1);
      return new Be.Corebvba.MVC.ImageResult(i,1,1);
   }
   finally
   {
      if (i != null) i.Dispose();
   }
}

This does need some better errorhandling, but I suppose you get the idea... (The _rDocument is a pointer to a Document repository which stores physical files. If you access your images from a database, you could simply use Image.FromStream instead of an Image.FromFile .In my document i reference the image as follows, et voila, automatic thumbnails :

<% var imgurl = Url.Action("ThumbImage", "Documents", new { id = d.ID,width=100,height=100 }); %>
<img src="<%=imgurl %>" style="float:left"/>

Tom's ramblings

ASP.NET MVC ImageHandler for thumbnails