Thank you for your answer. Because I want to study the files of .ptm or .rti , I hope get the uncompressed file of .ptm or .rti that I could study. Now I get compressed file of .ptm or .rti, I can not find the way to understand well the file.So I want to get the uncompressed file. Would you know the way to get the uncompressed file or the way to study the compressed file of .rti or .ptm? Thank you very much!