So the scenario is; how do we retrieve images that are stored in a database as a byte array and display them on a page utilizing Asp.net MVC.  The major hurtle that needs to be overcome is that a HTML image tag will not accept a source if it does not have the appropriate mime-type of image.

To meet that requirement in the controller add a new method that returns a type of FileContentResult.  Below is an example:

public FileContentResult GetSponsorImg(int id)
{
    var image = this.BaseContext.SponsorInfoes.Find(id).SponsorLogo;
    return image != null ? new FileContentResult(image, "image/png") : null;
}

What this method accomplishes is when the id of the image is passed in we can utilize Entity Frameworks find option and search the context to see if the image exist.  In this example we are searching for a sponsors logo image.

If the image is found we create a new FileContentResult and tag it as an image/png.  If the image is not found we simple return null.

In the MVC page add an image tag that looks similar to this:

<img src="@Url.Action("GetSponsorImg", "Home", new { id = item.Id })" alt="@item.Name" title="@item.Name" />

So what this code does, it tells the image source to call the method in the controller to get the image.  As stated above the controller gets the image from the database, flags it as an image and returns it.