Systems and methods for preserving and maintaining document integrity

1 SYSTEMS AND METHODS FOR PRESERVING AND MAINTAINING DOCUMENT INTEGRITY

This is a divisional application of application Ser. No. 1 1/090,224, filed Mar. 28, 2005 now U.S. Pat. No. 7,669,769, Which is incorporated herein by reference in its entirety for all purposes.

BACKGROUND

1. Field of the Invention

The present invention relates to the field of physical document management and, in particular, to systems and methods for preserving and maintaining the integrity of printed documents.

2. Description of Related Art

Electronic documents, such as those created using many document and/or word processing applications, generally have several layers of data. Each layer in the document, termed a “document layer,” contains some information related to the document or its contents. For example, the text seen by an end user creating, editing, or viewing a document may be represented in one layer of a document. Another layer may contain some of the drawings and/ or figures that are part of the document. Finally, a third layer may contain the background over which the text and drawings are displayed. One of the advantages of organizing documents in layers is that each layer may be edited and/ or created separately from other layers in the document. Thus, a layer may be changed without requiring any change in other layers associated with the document.

In addition to the layers described in the example above, a document may also contain “invisible layers.” These invisible layers may contain data pertaining to the document or its contents rather than actual document content that is seen by users. Such data is also often called meta-data. An invisible layer may include, for example, information about people who have edited or viewed any part of the document. Another invisible layer may contain indexing information such as terms that occur frequently in the document. Users editing or viewing the document do not normally see invisible layers. Menus provided by the document processing software may allow a user to explicitly request the information contained in an invisible layer in order to view the contents of that layer.

Invisible document layers may also be used by other applications or the operating system to enforce policies concerning the document. These policies may restrict the people who have access to the document or may prevent applications or users from making changes to portions of the document. Document layers may also be used to authenticate and ensure the integrity of a document. For example, an invisible document layer may contain a digital signature that can be used to establish that an electronic version of a document originated with the entity associated with the digital signature and that no changes were made to the document after it was digitally signed.

Although invisible layer data can be used electronically, for example, to authenticate the content of a document and protect against alteration while it is in electronic form, such protection ceases when the document is printed. Printed documents contain only the actual content of a document, and data stored in document layers is lost. Thus, once a document has been printed, a recipient has no way of determining where the document originated, or where it is stored, or whether the document was altered, even though such information may have been available in document layers.

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Preservation of layer data in printed documents would allow recipients of a printed document to automatically recreate preserved layer data, associate the preserved layer data with a document’s contents, and facilitate the enforcement and maintenance of policies associated with the printed document.

SUMMARY

In accordance with the present invention, systems and methods for maintaining and securing the integrity of printed documents are presented.

In some methods for preserving and maintaining document integrity, the contents of a document, or contents of a document layer may be encoded. In some embodiments, the encoded information may be stored in a document layer. In some embodiments, the encoded information may be represented using a 2-dimensional bar code. In some methods for preserving and maintaining document integrity, unused space available on each page or section of the document is determined along with the space required to print the encoded information. In some embodiments, if a page has sufficient space to print the code, the encoded information corresponding to a page or a document section may be printed on unused portions of that page or section along with its contents. In some embodiments, if there is insufiicient space to print the encoded information on a page or document section, then the encoded information may be printed after all the document content has been printed.

In some methods for preserving and maintaining document integrity, a printed document with encoded information corresponding to contents of pages, or sections of the document, may be scanned and digitized. In some embodiments, the printed encoded information may be in the form of a twodimensional bar code. In some embodiments, the scanned document data may be processed using character recognition and/or image processing algorithms to extract document content. In some embodiments, additional content may also be extracted from the encoded data printed on the document. In some embodiments, the content extracted from encoded data may be stored in a document layer. These and other embodiments are further explained below with respect to the following figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of a system for preserving and maintaining document integrity according to some embodiments of the invention.

FIG. 2 illustrates a flowchart describing the printing of a document with codes corresponding to the contents of layers associated with document sections, according to some embodiments of the invention.

FIG. 3 illustrates a method for adding encoded data to printed documents according to some embodiments of the invention.

FIG. 4 depicts a flowchart for extracting layer data from a printed document according to some embodiments of the invention.

DETAILED DESCRIPTION

In accordance with the present invention, methods and systems are provided for securing and maintaining document integrity. In some embodiments, an encoding is generated for each section of a document and, is based at least in part on the contents of the section and/or on document layers associated

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With that section. In at least some embodiments, the code may be stored in a document layer, and a representation of the encoded information may be printed along With the document.

In some embodiments, a physical document that does not contain any encoded information may be scanned and digitized. In some embodiments, the scanned document is processed using character recognition and/or image processing algorithms to extract document content. An code may then be generated for various document sections based, at least in part, on the content of those sections, and the document may be printed With a representation of the generated code.

In some embodiments, the space available on each document section and the space needed to print the code are determined. If there is adequate space, the code may be printed on blank or empty portions of the document, such as, for example, the document margins. In some embodiments, if there is inadequate physical space to print the code Within the document, the codes may be printed after the last page or last section of the document.

In some methods for preserving and maintaining document integrity, a printed document that includes encoded data may be scanned and digitized. In some embodiments, content may be extracted from the scanned document using character recognition and/or image processing techniques. In some embodiments, content may also be extracted from the encoded data printed on the document. In some methods for preserving and maintaining document integrity, extracted encoded data may be stored as a document layer.

FIG. 1 illustrates an exemplary system for preserving and maintaining document integrity according to embodiments of the invention. A computer software application consistent With the present invention may be deployed on a network of computers, as shown in FIG. 1, that are connected through communication links that allow information to be exchanged using conventional communication protocols and/ or data port interfaces.

As shown in FIG. 1, exemplary system 100 includes a computing device 110 and a server 130. Further, computing device 110 and server 130 may communicate over a connection 120, which may pass through network 140. Computing device 110 may be a computer workstation, desktop computer, laptop computer, or any other computing device capable of being used in a networked environment. Server 130 may be a platform capable of connecting to computing device 110 and other devices (not shown). Computing device 110 and server 130 may be capable of executing documentprocessing software (not shown) that allows the creation, editing, storing and processing of electronic documents. Document processing software could include commercially available document processing software such as Microsoft Word, Adobe Acrobat, or similar software. Documents created using the document processing software may be stored on computing device 110 or server 130 and made available to an application for preserving and maintaining document integrity according to embodiments of the invention.

Computing device 110 may also comprise removable media drive 150. Removable media drive 150 may include, for example, 3.5 inch floppy drives, CD-ROM drives, DVD ROM drives, CD:RW or DVD:RW drives, USB flash drives, and/ or any other removable media drives consistent with embodiments of the present invention. In some embodiments consistent with the present invention, portions of the software application may reside on removable media and be read and executed by computing device 110 using removable media drive 150. In some embodiments, documents processed by applications executing methods for preserving and maintain

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ing document integrity consistent with present invention may be stored on removable media and accessed through removable media drive 150.

Connection 120 couples computing device 110, server 130, printer 160, and scanner 170 and may be implemented as a wired or wireless connection using conventional communication protocols and/or data port interfaces. In general, connection 120 can be any communication channel that allows transmission of data between the devices. In one embodiment, for example, the devices may be provided with conventional data ports, such as Universal Serial Bus (“USB”), Small Computer Systems Interface (“SCSI”), IEEE 1394 High Performance Serial Bus (“Firewire”), and/or coaxial cable ports for transmission of data through the appropriate connection 120. In some embodiments, connection 120 may be a low-bandwidth connection, for example, a Digital Subscriber Line (DSL), an Asymmetric Digital Subscriber Line (ADSL), or a cable connection.

Network 140 may be, for example a Local Area Network (LAN), a Wide Area Network (WAN), or the Internet. In some embodiments consistent with the present invention, information sent over network 140 may be encrypted to ensure the security of the data being transmitted.

Printer 160 and Scanner 170 are connected to network 140 through connection 120. In some embodiments, printer 160 and scanner 170 may be connected directly to computing device 110 and/or server 130. Printer 160 may be used to print documents containing encoded information, such as twodimensional bar codes, in accordance with some methods for preserving and maintaining document integrity. In some embodiments, the information contained in the document, as well as meta-data information associated with the document, such as indexing information, content descriptions, access lists, times of creation, editing, etc., may be encoded and stored as a document layer. In some embodiments, the encoded information may be printed on paper or other media using a two-dimensional bar code, or other machine-readable formats. In some embodiments, printer 170 may be a color printer capable of printing encoded information in the form of multi-colored two-dimensional bar codes. Documents stored on computing device 110, server 130, or on removable media may be printed on printer 170. Scanner 160 may be used to scan documents, including printed documents containing encoded information, in accordance with some methods of preserving and maintaining document integrity. Both printer 170 and scanner 160 may contain automatic document feeders to allow batch processing of documents. In some embodiments, scanner 160 may be capable of reading machinereadable code printed on documents. In some embodiments, documents scanned using scanner 170 may be stored on computing device 110 and/or server 130 for additional processing.

A computer software application consistent with the present invention may be deployed on any of the exemplary computers, as shown in FIG. 1. For example, computing device 110 could execute software that may be downloaded directly from server 130. In some embodiments a software application implementing methods for preserving and maintaining document integrity may be distributed between the various computing systems shown in FIG. 1.

FIG. 2 is a flowchart describing one exemplary method of printing of a document with codes corresponding to the contents of layers associated with document pages, or sections, according to the invention. In some embodiments, an application implementing steps in flowchart 200 may be executed on computing device 110, or server 130. The application may operate on electronic documents stored on computing device