Sitecore command for opening the image editor app from Experience Editor

EditImage.cs

namespace SitecoreAndMore
{
    using System;
    using Sitecore;
    using Sitecore.Data.Fields;
    using Sitecore.Data.Items;
    using Sitecore.Diagnostics;
    using Sitecore.Exceptions;
    using Sitecore.Globalization;
    using Sitecore.Shell.Applications.ContentEditor;
    using Sitecore.Shell.Applications.WebEdit.Commands;
    using Sitecore.Shell.Framework.Commands;
    using Sitecore.Text;
    using Sitecore.Web;
    using Sitecore.Web.UI.Sheer;

    [Serializable]
    public class EditImage : WebEditImageCommand
    {
        public override void Execute(CommandContext context)
        {
            Assert.ArgumentNotNull(context, "context");
            ExplodeParameters(context);
            string formValue = WebUtil.GetFormValue("scPlainValue");
            context.Parameters.Add("fieldValue", formValue);

            Context.ClientPage.Start(this, "Run", context.Parameters);
        }

        protected static void Run(ClientPipelineArgs args)
        {
            Assert.ArgumentNotNull(args, "args");
            Item itemNotNull = Client.GetItemNotNull(args.Parameters["itemid"], Language.Parse(args.Parameters["language"]));
            itemNotNull.Fields.ReadAll();
            Field field = itemNotNull.Fields[args.Parameters["fieldid"]];
            Assert.IsNotNull(field, "field");
            string xml = args.Parameters["fieldValue"];
            if (!args.IsPostBack)
            {
                string str = StringUtil.GetString(new string[2] { field.Source, "/sitecore/media library" });
                if (xml.Length > 0) { 
                    xml = new XmlValue(xml, "image").GetAttribute("mediaid");
                }
                string path = xml;
                if (str.StartsWith("~", StringComparison.InvariantCulture))
                {
                    if (string.IsNullOrEmpty(path)) { 
                        path = StringUtil.Mid(str, 1);
                    }
                    str = "/sitecore/media library";
                }
                Language language = itemNotNull.Language;
                Item obj1 = Client.ContentDatabase.GetItem(str, language);
                if (obj1 == null)
                    throw new ClientAlertException("The source of this Image field points to an item that does not exist.");

                Item image = !string.IsNullOrEmpty(path) ? Client.ContentDatabase.GetItem(path, language) : null;
                if (image == null)
                    throw new ClientAlertException("Please select an image before opening the edit function.");

                UrlString urlString = new UrlString();
                urlString.Append("sc_content", image.Database.Name);
                urlString.Append("id", image.ID.ToString());
                urlString.Append("la", image.Language.ToString());
                urlString.Append("vs", image.Version.ToString());
                if (!string.IsNullOrEmpty(args.Parameters["frameName"]))
                    urlString.Add("pfn", args.Parameters["frameName"]);

                SheerResponse.ShowModalDialog("/sitecore/shell/Applications/Media/Imager?" + urlString, "1200px", "700px", string.Empty, IsDebugging);
                args.WaitForPostBack();
            }
        }
    }
}