Correct picture file extension

private void CorrectPictureExtention(string PictureFile)
{
 FileInfo FileData = My.Computer.FileSystem.GetFileInfo(PictureFile);
 if (FileData.Exists == true) {
  Bitmap PictureBitmap = null;
  try {
   PictureBitmap = Bitmap.FromFile(PictureFile);
  } catch {
  }
  if (PictureBitmap != null) {
   Dictionary GuidDictionary = new Dictionary();
   GuidDictionary.Add("b96b3cab-0728-11d3-9d7b-0000f81ef32e", ".Bmp");
   GuidDictionary.Add("b96b3cac-0728-11d3-9d7b-0000f81ef32e", ".Emf");
   GuidDictionary.Add("b96b3cb0-0728-11d3-9d7b-0000f81ef32e", ".Gif");
   GuidDictionary.Add("b96b3cb5-0728-11d3-9d7b-0000f81ef32e", ".Ico");
   GuidDictionary.Add("b96b3cae-0728-11d3-9d7b-0000f81ef32e", ".Jpg");
   GuidDictionary.Add("b96b3caf-0728-11d3-9d7b-0000f81ef32e", ".Png");
   GuidDictionary.Add("b96b3cb1-0728-11d3-9d7b-0000f81ef32e", ".Tif");
   GuidDictionary.Add("b96b3cad-0728-11d3-9d7b-0000f81ef32e", ".Wmf");
   string ImageType = "";
   GuidDictionary.TryGetValue(PictureBitmap.RawFormat.Guid.ToString, ImageType);
   PictureBitmap.Dispose();
   if (!string.IsNullOrEmpty(ImageType)) {
    if (!string.IsNullOrEmpty(FileData.Extension)) {
     if (FileData.Extension != ImageType) {
      My.Computer.FileSystem.RenameFile(FileData.FullName, FileData.Name.Replace(FileData.Extension, "") + ImageType);
     } else {
      My.Computer.FileSystem.RenameFile(FileData.FullName, FileData.Name + ImageType);
     }
    }
   }
  }
 }
}