This dialog box appears whenever you click the Settings button in the PDF Create Profiles dialog box with the MRC and Searchable checkboxes selected.
In this dialog box you can make your settings to create a Searchable PDF from image files (including Image only PDF files) with MRC compression. Remember that image quality and file size have an inverse relationship. The higher the compression, the smaller the file, and the less quality the image will have.
MRC Image Quality
Select one of the following options:
Minimal: Select this to achieve the smallest file size while the image quality is lower.
Good: Select this to reduce file size while keeping a good image quality.
Superb: Select this to reduce file size as much as possible without degrading the image quality. This produces the best possible image quality.
OCR Language
OCR is needed for extracting text from images to make image files searchable. Select the language that appears in the source document.
Reject character
Unrecognizable characters are represented by a reject character (a tilde: ~ by default) . For example, if the OCR could not recognize the J in REJECT, and ~ is the reject character, the string RE~ECT would appear in your document.
Type the character you want to use in the Reject character edit box. Try to choose a character that will not appear in your documents.
Auto orient pages
Select this if you let Power PDF to choose page orientation (landscape or portrait) for each page.
Auto straighten pages
Select this to let Power PDF rotate the pages to align margins to the vertical/horizontal if needed.
Note
When an input file is a text file or has an accessible text layer, a normal searchable PDF is created without OCR running, so the OCR language and reject character settings are not used in those cases.