Use theOCR Settings dialog box to change the recognition language and the reject character. Launch this dialog box from Power PDF (in the Convert Pages dialog box) or from the Convert Assistant.
To achieve the best accuracy, select only the languages your document contains. Multiple language selection is allowed; see Multiple language selection for details.
You can set Automatic Language Detection to have the program detect the language of the document, based on all languages with a dictionary. See Language Selection for details on how it operates, along with a full list of supported and dictionary-supported languages.
Unrecognizable characters are represented by a reject character which is a tilde ~ by default. You can optionally change the reject character.