Read pdf text output is incorrect

Hi all,
I have some pdf files, i used read pdf text, but the out put is same and sometimes the output result is incorrect, please help me to check, thank you.
Invoice Cover0.pdf (63.4 KB)
Invoice Cover1.pdf (56.4 KB)
Invoice Cover2.pdf (52.6 KB)


It seems that some special protection is applied. Even if we open the file with ActobatReder or any other pdf viewer and copy the text, it’s illegal characters. Perhaps there is no way but using Read PDF with OCR activity.