ASP.NET

///
/// imageData is the data loaded from the database in the Page_Load
///
private void ShowImageData(byte[] imageData)
    {
        // Clear Response buffer
        Response.Clear();

        // Set ContentType to the ContentType of our file
        Response.ContentType = "image/jpeg"; 

        // Write data out of database into Output Stream
        Response.OutputStream.Write(imageData, 0, imageData.Length);

        // End the page
        Response.End();
    }