How to return image file using custom route to cache the image file?

Question

I'm having a hard time figuring out on how to cache the image from a blob stream.
This is my first code and it works to download the return the image file:

HTML PART:

<img src="@Url.Action("GetImage", "Asset")?photoId=@SessionData.ProfilePic.PhotoID&type=3"/>  

CONTROLLER:

public ActionResult GetImage(long photoId, PhotoType type)
{   
    byte[] img = <Code that fetches image byte from blob stream>;
    return File(img, "image/png");            
}

But this fail to cache in browser.
I am thinking that if the url seems to be like this:

http://stackoverflow.com/Asset/GetImage/1/2  

the image can now be cache?
So I create another route:

routes.MapRoute(
    "Upload",
    "Asset/GetImage/{photoId}/{type}",
    new { controller = "Asset", action = "GetImage" }
);

and access the image like this:

http://stackoverflow.com/Asset/GetImage/1/2
<img src="http://stackoverflow.com/Asset/GetImage/1/2" />

But I always get:

Failed to load resource: the server responded with a status of 404 (Not Found)   

Now my questions are:

1. Am I right of thinking that when the url is formatted like this http://stackoverflow.com/Asset/GetImage/1/2 it can now be cache by the browser?
2. Why do I get this error? Failed to load resource: the server responded with a status of 404 (Not Found) What's wrong with my route?

Hope someone could help.

EDIT

This is my full Routes:

routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

routes.MapRoute(
    "Upload",
    "Asset/GetImage/{photoId}/{type}",
    new { controller = "Asset", action = "GetImage" }
);

var route = routes.MapRoute(
        "Gallery",
        "",
        new { controller = "Auth", action = "Login" },
        new[] { "Project.Areas.Gallery.Controllers" }
    );

route.DataTokens["area"] = "Gallery";  

And still getting the error Failed to load resource: the server responded with a status of 404 (Not Found) , what could be wrong ?

EDIT2

The list of meta tags I've used:

<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="description" content="">
<meta name="author" content="">
<meta name="viewport" content="width=device-width,initial-scale=1">
<meta http-equiv="imagetoolbar" content="false">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

Answer 1

The following works for me

Action Method

[OutputCache(Duration = 20, VaryByParam = "photoId")]
public ActionResult GetImage(long photoId, long type)
{
    byte[] img = System.IO.File.ReadAllBytes(Server.MapPath("~/Images/aspNetHome.png"));
    return File(img, "image/png");
}

HTML

<img src="~/Home/GetImage/1/2" alt="" />

Route added to Global asax

routes.MapRoute(
    "Upload",
    "Home/GetImage/{photoId}/{type}",
    new { controller = "Home", action = "GetImage" }
);

Response headers from Fiddler

Referer: http:// localhost /MvcApplicationImageTest/Home/GetImage/1/2*

HTTP/1.1 200 OK
Cache-Control: private, max-age=20
Content-Type: image/png
Expires: Wed, 01 Aug 2012 05:08:25 GMT
Last-Modified: Wed, 01 Aug 2012 05:08:05 GMT
Server: Microsoft-IIS/7.5
X-AspNetMvc-Version: 4.0
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Date: Wed, 01 Aug 2012 05:08:10 GMT
Content-Length: 3736

EDIT following comments

OutputCacheAttribute removed

HTTP/1.1 200 OK
Cache-Control: private
Content-Type: image/png
Server: Microsoft-IIS/7.5
X-AspNetMvc-Version: 4.0
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Date: Thu, 02 Aug 2012 04:52:02 GMT
Content-Length: 3736

As you can see in the headers, Cache-Control just shows private and not Cache-Control: no-cache, Expires: -1, Pragma: no-cache

I now believe you must be explicitly disabling the cache somehow? Do you have any META tags in your view or layout pages? eg

<meta http-equiv="cache-control" content="no-cache" />

<meta http-equiv="pragma" content="no-cache" />

<meta http-equiv="expires" content="-1" />