var
  iIEBitmap: TIEBitmap;
  iImageEnIO: TImageEnIO;
  iImgStream: TMemoryStream;
  iOutStream: TMemoryStream;
begin
  iIEBitmap := TIEBitmap.Create;
  try
    iImageEnIO := TImageEnIO.Create(Self);
    try
      iImgStream := TMemoryStream.Create;
      try
        iOutStream := TMemoryStream.Create;
        try
          iImageEnIO.AttachedIEBitmap := iIEBitmap;
          if (FileExists(FFileName)) then
          begin
            iImageEnIO.LoadFromFileAuto(FFileName);
            iImageEnIO.Params.EXIF_XPTitle := 'Photograph of Dolly';
            iImageEnIO.Params.EXIF_XPSubject := 'Dolly';
            // This is important if you want change some EXIF fields
            iImageEnIO.Params.EXIF_HasEXIFData := True;
            iImageEnIO.AttachedIEBitmap.Resize(300, 300);
            iImageEnIO.InjectJpegEXIF(iImgStream, iOutStream);
            iImageEnIO.SaveToStream(iOutStream, ioJPEG);
            iImgStream.Position := 0;
            // ...
            Response.ContentStream := iImgStream;
          end;
        finally
          iOutStream.Free;
        end;
      finally
        iImgStream.Free;
      end;
    finally
      iImageEnIO.Free;
    end;
  finally
    iIEBitmap.Free;
  end;
end;