new Redaction()
A redaction annotation (PDF 1.7) identifies content that is intended to
be removed from the document. The intent of redaction annotations is to
enable the following:
a)Content identification. A user applies redact annotations that specify
the pieces or regions of content that should be removed. Up until the
next step is performed, the user can see, move and redefine these
annotations.
b)Content removal. The user instructs the viewer application to apply
the redact annotations, after which the content in the area specified
by the redact annotations is removed. In the removed content's place,
some marking appears to indicate the area has been redacted. Also, the
redact annotations are removed from the PDF document.
Redaction annotations provide a mechanism for the first step in the
redaction process (content identification). This allows content to be
marked for redaction in a non-destructive way, thus enabling a review
process for evaluating potential redactions prior to removing the
specified content.
Redaction annotations shall provide enough information to be used
in the second phase of the redaction process (content removal).
This phase is application-specific and requires the conforming reader
to remove all content identified by the redaction annotation, as well
as the annotation itself.
Conforming readers that support redaction annotations shall provide
a mechanism for applying content removal, and they shall remove all
traces of the specified content. If a portion of an image is contained
in a redaction region, that portion of the image data shall be destroyed;
clipping or image masks shall not be used to hide that data.
Such conforming readers shall also be diligent in their consideration
of all content that can exist in a PDF document, including XML Forms
Architecture (XFA) content and Extensible Metadata Platform (XMP)
content.