SharePoint Picture Library -Get Image from Folder using CAML Query in C#

public DataTable GetFolderImageFromPicLib(string folderPath)

        {

           

            DataTable dt = new DataTable();

            dt.Columns.Add("ID", typeof(string));

            dt.Columns.Add("Keywords", typeof(string));

            dt.Columns.Add("RequiredField", typeof(string));

            dt.Columns.Add("Title", typeof(string));

            dt.Columns.Add("FileName", typeof(string));

            dt.Columns.Add("FolderPath", typeof(string));

            dt.Columns.Add("FileDirRef", typeof(string));

            SPSecurity.RunWithElevatedPrivileges(delegate ()

            {

                using (SPSite site = new SPSite(SPContext.Current.Web.Url))

                {

                    using (SPWeb web = site.OpenWeb())

                    {

                      

                        SPPictureLibrary lib = (SPPictureLibrary)web.Lists.TryGetList("My Pic Library");

                       // folderPath = "/sameple/" + lib.Title + folderPath;

                        folderPath = "/" + lib.Title + folderPath;

                        if (lib != null)

                        {

                            SPQuery query = new SPQuery();

                            query.ViewXml = "<View Scope=\"RecursiveAll\"> " +

                  "<Query>" +

                  "<Where>" +

                              "<Eq>" +

                                  "<FieldRef Name=\"FileDirRef\" />" +

                                  "<Value Type=\"Text\">"+ folderPath + "</Value>" +

                               "</Eq>" +

                  "</Where>" +

                  "</Query>" +

                  "</View>";

                            DataRow row;

                            SPListItemCollection lstImages = lib.GetItems(query);

                            foreach (SPListItem item in lstImages)

                            {

                                string folderName = Convert.ToString(item["RequiredField"]);

                                row = dt.NewRow();

                                row["ID"] = item["ID"];

                                row["FileDirRef"] = item["FileDirRef"];

                                row["Keywords"] = item["Keywords"];

                                row["RequiredField"] = item["RequiredField"];

                                row["FolderPath"] = folderName.Remove(folderName.LastIndexOf('/') + 1);

                                row["Title"] = item["Title"];

                                row["FileName"] = item["FileName"];

                                dt.Rows.Add(row);

                            }

                        }

                    }

                }

            });

            return dt;

        }