I.R.I.S. Readiris 14 for Windows User Guide - Manual (Page 117)

Section 9: Saving Documents
124
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PDF Image. When you select this file type, Readiris doesn't
execute the text recognition on your document. Your PDF file
will not be text-searchable, it only contains the image of your
original document.
The PDF options
Create bookmarks
Bookmarks are types of links inside a PDF document, which
contain representative information about the section they are linked
to. Bookmarks give structure to your PDF documents. They are
grouped in the Bookmarks panel in the Navigation pane.
In Readiris, the option Create bookmarks creates a bookmark for
each text zone, image zone and table zone inside a PDF file.