U.S. patent application number 11/468258 was filed with the patent office on 2007-03-08 for image management system and methods using digital watermarks.
Invention is credited to Lorie Clements, Neil A. Lofgren, Phillip R. Patterson, Geoffrey B. Rhoads.
Application Number | 20070052730 11/468258 |
Document ID | / |
Family ID | 37829627 |
Filed Date | 2007-03-08 |
United States Patent
Application |
20070052730 |
Kind Code |
A1 |
Patterson; Phillip R. ; et
al. |
March 8, 2007 |
Image management system and methods using digital watermarks
Abstract
Digital watermarking technology is used in an image management
system. Images are uniquely identified by digital watermarking. The
images are stored so as to be indexed according to unique
identifiers. In one embodiment, related images are linked together
by a unique watermark identifier. The unique watermark identifier
is also used to manage metadata, and provide forensic tracking.
Watermark identifiers can be used to carry or access security
clearance information associated with an image or other media.
Other embodiments are provided as well.
Inventors: |
Patterson; Phillip R.;
(Sherwood, OR) ; Clements; Lorie; (Portland,
OR) ; Lofgren; Neil A.; (Portland, OR) ;
Rhoads; Geoffrey B.; (West Linn, OR) |
Correspondence
Address: |
DIGIMARC CORPORATION
9405 SW GEMINI DRIVE
BEAVERTON
OR
97008
US
|
Family ID: |
37829627 |
Appl. No.: |
11/468258 |
Filed: |
August 29, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09858336 |
May 15, 2001 |
7098931 |
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11468258 |
Aug 29, 2006 |
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09800093 |
Mar 5, 2001 |
7061510 |
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11468258 |
Aug 29, 2006 |
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60284163 |
Apr 16, 2001 |
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60284776 |
Apr 18, 2001 |
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Current U.S.
Class: |
345/634 |
Current CPC
Class: |
G06F 21/6209 20130101;
G06T 1/0021 20130101; G01C 11/00 20130101 |
Class at
Publication: |
345/634 |
International
Class: |
G09G 5/00 20060101
G09G005/00 |
Claims
1. A method comprising: receiving media including digital
watermarking embedded therein through alterations to data
representing the media, the digital watermarking including at least
a first plural-bit identifier; analyzing the media to obtain the
plural-bit identifier; communicating the plural-bit identifier to a
remote database, the remote database including a plurality of usage
rights indexed therein, the usage rights including a required
security clearance associated with the plural-bit identifier;
receiving information indicating the required security clearance
from the remote database; obtaining information indicating a user's
security clearance level; determining whether to allow access to
the media by the user based at least in part on whether the
information indicating a user's security clearance level
corresponds with the received information indicating the required
security clearance.
2. A method of maintaining images in a database, wherein a first
image includes a digital watermark embedded therein, the digital
watermark comprising a first unique identifier, said method
comprising: storing the first image to be indexed by the first
unique identifier; storing information related to the first image;
and linking the first image and the related information by the
first unique identifier.
3. A method according to claim 2 further comprising: in the
database, storing at least a second image and linking the first
image and the second image with the first unique identifier.
4. A method according to claim 3, wherein the second image
comprises a derivative of the first image.
5. A method according to claim 4, wherein the second image includes
a digital watermark embedded therein, the digital watermark
comprising a second unique identifier, and wherein said method
further comprises linking the second unique identifier to the first
unique identifier.
6. A method according to claim 4, wherein the related information
comprises a history of the image.
7. The method according to claim 6, wherein the history comprises
at least one of user usage, creation time, transmission, printing,
and image checkout.
8. The method according to claim 2, wherein the database comprises
a plurality of databases.
9. The method according to claim 2 wherein the related information
comprises at least one item of information selected from a group
comprising: metadata, location, date, permission level, security
access levels, analyst comments, notes, files, and past usage
information.
10. A method to monitor images in a system, the system comprising
at least a first user terminal to communicate with a second user
terminal and with a database, the images comprising at least a
first image digitally watermarked to include a first identifier,
said method comprising: determining a security level associated
with the first image; comparing the first image security level with
a user security level; and allowing access to the first image based
on a result of said comparing.
11. The method according to claim 10, further comprising recording
a transmission in the database of the first image from the first
user terminal to the second user terminal.
12. The method according to claim 10, wherein said determining
comprises: decoding the digital watermark to determine the first
identifier; and interrogating the database with the first
identifier to retrieve the security level.
13. The method according to claim 10, wherein said first image's
digital watermark includes security level data, and wherein said
determining comprises decoding the digital watermark to determine
the security level.
14. The method according to claim 10, wherein the user security
level comprises at least one of a security level for a user and a
security level for a user terminal.
15. The method according to claim 14 wherein when the result is a
match between the first image security level and the user security
level access is allowed.
16. The method according to claim 15 wherein the match indicates
that the user security level is equal to or greater than the first
image security level.
17. The method according to claim 15, further comprising recording
access to the image.
Description
RELATED APPLICATION DATA
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/858,336, filed May 15, 2001 (issuing as
U.S. Pat. No. 7,098,931). The U.S. Ser. No. 09/858,336 application
claims the benefit of U.S. Provisional Application Nos. 60/284,163
filed Apr. 16, 2001, entitled "Watermark Systems and Methods," and
60/284,776 filed Apr. 18, 2001, entitled "Using Embedded
Identifiers with Images." The 09/858,336 application is also a
continuation-in-part of assignee's U.S. patent application Ser. No.
09/800,093, entitled "Geo-Referencing of Aerial Imagery Using
Embedded Image Identifiers and Cross-Referenced Data Sets," filed
Mar. 5, 2001 (now U.S. Pat. No. 7,061,510).
[0002] This patent application is also related to assignee's U.S.
patent application Ser. No. 09/833,013, entitled "Digitally
Watermarked Maps and Signs and Related Navigational Tools," filed
Apr. 10, 2001 (published as US 2002-0147910 A1).
FIELD OF THE INVENTION
[0003] The present invention relates to image management and
processing, and is particularly illustrated in the context of a
satellite and other aerial imagery management system.
BACKGROUND AND SUMMARY OF THE INVENTION
[0004] Aerial imagery has vastly improved since the Wright brothers
first took to the sky. Indeed, there have been many improvements in
the photography and digital imaging fields.
[0005] While the earliest aerial imagery relied on conventional
film technology, a variety of electronic sensors are now more
commonly used. Some collect image data corresponding to specific
visible, UV or IR frequency spectra (e.g., the MultiSpectral
Scanner and Thematic Mapper used by the Landsat satellites). Others
use wide band sensors. Still others use radar or laser systems
(sometimes stereo) to sense topological features in 3 dimensions.
Some satellites even collect ribbon imagery (e.g., a raster-like,
1-dimensional terrestrial representation, which is pieced together
with other such adjacent ribbons).
[0006] The quality of the imagery has also constantly improved.
Some satellite systems are now capable of acquiring image and
topological data having a resolution of less than a meter. Aircraft
imagery, collected from lower altitudes, provides still greater
resolution.
[0007] A vast amount of aerial imagery is constantly being
generated and collected. Management of the resulting large data
sets is a growing problem. In today's digital world, images are
routinely manipulated, even on home computers. Management of
resulting image ancestry, image derivates and related metadata is
increasingly difficult.
[0008] According to one aspect of the present invention, a digital
watermark-based image management system helps solve these and other
problems. A digital watermark is ideally employed as an enabler to
access a related family of images, linked in a database (or other
data structure) via digital watermark identifiers. Watermark
identifiers can also be used to identify the source of an image,
track images and documents, document a distribution chain, and
identify unlabeled hard copy images. According to another aspect,
digital watermarks help to provide security, monitoring and
gatekeeper-like functions.
[0009] Digital watermarking is a form of steganography that
encompasses a great variety of techniques by which plural bits of
digital data are hidden in some other object without leaving
human-apparent evidence of alteration.
[0010] Digital watermarking may be used to modify media content to
embed a message or machine-readable code into the content. The
content may be modified such that the embedded code is
imperceptible or nearly imperceptible to the user, yet may be
detected through an automated detection process.
[0011] Most commonly, digital watermarking is applied to media such
as images, audio signals, and video signals. However, it may also
be applied to other types of data, including documents (e.g.,
through line, word or character shifting, through texturing,
graphics, or backgrounds, etc.), software, multi-dimensional
graphics models, and surface textures of objects.
[0012] The assignee's U.S. Pat. No. 6,122,403, and co-pending U.S.
patent application Ser. No. 09/503,881 (now U.S. Pat. No.
6,614,914), detail suitable digital watermarking techniques in
which values of pixels, e.g., in a 100.times.100 pixel patch, can
be slightly altered so as to convey a plural-bit payload, without
impairing use of the pixel data for its intended purpose. The
payload may be on the order of 2-256 bits, depending on the
particular form of encoding (e.g., convolution, turbo, or BCH
coding can be employed to provide some error-correcting
capability), and the number of bits per pixel. Larger payloads can
be conveyed through larger image patches. (Larger payloads can also
be conveyed by encoding the information in a less robust fashion,
or by making the encoding more relatively visible.). The watermark
payload can convey an image identifier, and may convey other
metadata as well. In some embodiments, the component image files
are tagged both by digital watermark identifiers and also by
conventional out-of-band techniques, such as header data, thereby
affording data redundancy. Of course, there are many watermarking
techniques known to those skilled in the art, and such may be
suitably interchanged with the present invention.
[0013] Digital watermarking systems typically have two primary
components: an embedding component that embeds the watermark in the
media content, and a reading component that detects and reads the
embedded watermark. The embedding component embeds a watermark
pattern by altering data samples of the media content. The reading
component analyzes content to detect whether a watermark pattern is
present. In applications where the watermark encodes information,
the reading component extracts this information from the detected
watermark. Commonly assigned U.S application Ser. No. 09/503,881,
filed Feb. 14, 2000, discloses various encoding and decoding
techniques. U.S. Pat. No. 5,862,260 discloses still others.
[0014] Watermarking may be performed in stages, at different times.
For example, a unique identifier can be watermarked into an image
relatively early in the process, and other information (such as
finely geo-referenced latitude/longitude) can be watermarked later.
A single watermark can be used, with different payload bits written
at different times. (In watermark systems employing pseudo-random
data or noise (PN), e.g., to randomize some aspect of the payload's
encoding, the same PN data can be used at both times, with
different payload bits encoded at the different times.).
[0015] Alternatively, different watermarks can be applied to convey
different data. The watermarks can be of the same general type
(e.g., PN based, but using different PN data). Or different forms
of watermark can be used (e.g., one that encodes by adding an
overlay signal to a representation of the image in the pixel
domain, another that encodes by slightly altering DCT coefficients
corresponding to the image in a spatial frequency domain, and
another that encodes by slightly altering wavelet coefficients
corresponding to the image. Of course, other watermarking
techniques may be used as suitable replacements for those discussed
above.).
[0016] In some multiple-watermarking approaches, a first watermark
is applied before a satellite image is segmented into patches. A
later watermark can be applied after segmentation. (The former
watermark is typically designed so as to be detectable from even
small excerpts of the original image.)
[0017] A watermark can be applied by an imaging instrument. In some
embodiments, the image is acquired through an LCD optical shutter,
or other programmable optical device, that imparts an inconspicuous
patterning to the image as it is captured. (One particular optical
technique for watermark encoding is detailed in U.S. Pat. No.
5,930,369.). Or the watermarking can be effected by systems in a
satellite (or other aerial platform) that process the acquired data
prior to transmission to a ground station. In some systems, the
image data is compressed for transmission--discarding information
that is not important. The compression algorithm can discard
information in a manner calculated so that the remaining data is
thereby encoded with a watermark.
[0018] A ground station receiving the satellite transmission can
likewise apply a watermark to the image data. So can each
subsequent system through which the data passes, if desired.
[0019] Preferably, such watermarking processes are secure and
cannot be replicated by unauthorized individuals.
[0020] The foregoing and additional features and advantages of the
present invention will be more readily apparent from the following
detailed description with reference to the following figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a functional block diagram illustrating a digital
watermarking process.
[0022] FIG. 2 illustrates components of an image management
system.
[0023] FIG. 3 illustrates associating related images and
information with a digital watermark identifier.
[0024] FIG. 4 is a functional block diagram illustrating
gatekeepers in a network.
[0025] FIGS. 5 and 6 are flow diagrams illustrating gate-keeping
methods and processes according to the FIG. 4 embodiment.
DETAILED DESCRIPTION
[0026] For expository convenience, the following discussion focuses
on satellite and other aerial "imagery" to illustrate the
principles of the invention. The principles of the invention,
however, are equally applicable to other forms of imagery,
including non-aerial imagery. Accordingly, the term "image" should
be used to encompass other data sets, and the term "pixel" should
be construed to encompass component data from such other data sets.
The term "image" should also be construed to include both digital
and analog data sets.
[0027] Watermarking Images
[0028] With reference to FIG. 1, an image (or image data) 10 is
captured from an aerial platform 11, such as an aircraft,
satellite, balloon, unmanned aircraft, etc. The image 10 is
communicated to a receiving or ground station 12. (In some
instances, the image signal may be relayed through various aerial
and/or other ground stations before reaching ground station 12.).
Ground station 12 preferably includes a watermark embedder 12a,
which embeds a digital watermark with the image 10, to produce a
digitally watermarked image 13.
[0029] A digital watermark is typically embedded in a digital
representation of the image 10. Although not required, the digital
watermark preferably survives transformation to various analog
representations (e.g., printing) as well. The digital watermark
includes a watermark identifier (ID). In the preferred embodiment,
each image is digitally watermarked to include a unique watermark
ID. The ID typically includes plural-bit data, e.g., in the range
of 2-256 bits. In one embodiment, a digital watermark (and
identifier) is redundantly embedded within an image to improve
robustness. For example, an image is divided into tiles or
sections, and each tile or section is embedded with the digital
watermark (and ID). Alternatively, a subset of the sections are
embedded. Such techniques help to ensure the robustness of a
watermark, particularly when an image is to be manipulated (e.g.,
clipped, cut-and-pasted, resized, rotated, etc.).
[0030] Digitally watermarked image 13 is stored in a database 14.
(A watermarked image can be directly communicated to database 14,
transferred via a storage medium and/or relayed to database 14.).
Database 14 preferably manages images and/or related data. Database
software, e.g., such as provided by Microsoft, Oracle, Sun
Microsystems, etc., can be executed by a computer or server to help
maintain database 14. Of course, database 14 can be maintained by a
ground station 12 system, or be maintained in a remotely located
network. In one embodiment, database 14 communicates with a
network, such as a LAN, WAN, dedicated network, private network,
etc. In some embodiments, database 14 includes a plurality of
databases. In this case, at least one database maintains image
data, while at least a second database maintains related
information (e.g., metadata, related files, comments, file history,
and/or security clearance information, etc.). Here, metadata is
broadly defined to include a variety of information such as
creation data, geo-location information, ancestry data, security
information, access levels, copyright information, security
classifications, usage rights, and/or file history, etc.
[0031] Image 13 and/or any related information is preferably stored
and indexed according to watermark IDs. For example, a watermark ID
provides a thread by which images and related information are
grouped, stored and/or indexed. (The dashed lines in FIG. 1
represent this optional embodiment.).
[0032] Optionally, image data is communicated to a second database
15. Database 15 can be used to maintain original image 10 and/or an
original watermarked image 13.
[0033] Image and Derivative Image Management Using Digital
Watermarks
[0034] As indicated above, a problem faced by image management
systems is how to efficiently manage an image's ancestry and
related information. Normal image processing (e.g., scaling,
cropping, rotating, clipping, resizing, cut-and-pasting image
blocks, and/or marking, etc.) of an "original" image results in a
"derivative" image. In conventional systems, derivative images
frequently retain minimal, if any, related metadata. The metadata,
such as that stored in header or footer files, is easily separable
from derivative images. Separation results in a significant loss of
information, particularly for a derivative image. One conventional
solution is to manually record an image identifier as an image
moves through an exploitation (or derivative) process. This manual
recording process is labor intensive and cumbersome at best.
[0035] A better solution, as disclosed in this application, is to
place a unique digital watermark ID within an image to enable
database linking and indexing. Metadata contained within the
database can be then associated with a specific image, or with a
family of images, via the unique watermark ID. With reference to
FIG. 2, a user terminal 18 retrieves a digitally watermarked image
001 from database 14. User terminal 18 preferably includes a
processor, memory and suitable software instructions to facilitate
digital watermark detection and/or embedding. The user terminal 18
will preferably include an operating system, such as Windows,
Windows NT, Linux, etc., and image-handling (and editing) software.
Suitable image-handling software can be obtained from Microsoft,
Adobe, SRI and Erdas, among others. Preferably, both the watermark
detecting software and the image-handling software are compatible
with various types of image formats, such as bit-maps, JPEG files,
TIF files, etc. (However, such compatibility is not required.).
[0036] Watermark detection software executing in user terminal 18
analyzes image 001. The watermark detection software can be called
by the imaging software, may operate as a plug-in, or may be even
integrated with the image-handling software, operating system, or
other software module. The watermark detection software extracts
the unique watermark identifier (e.g., ID-1) embedded within image
001. Having obtained the identifier (ID-1), the user terminal 18
can optionally communicate with database 14 to retrieve related
information, such as metadata, files, and related images. For
example, the watermark ID-1 is used to interrogate database 14 to
retrieve information regarding the geo-coordinates for the image,
the time and date taken, analyst comments, and/or analyst
information, etc. Preferably, the watermark ID-1 can also be used
to index any derivative images, e.g., derivative 001. (In this
case, derivative 001 is an image derived from image 001.).
[0037] In a preferred embodiment, since each image includes a
unique identifier, derivative 001 includes a watermark identifier
(e.g., ID-5), which is unique from the corresponding original image
001 (e.g., identifier ID-1). Derivative 001 and image 001 are
associated (e.g., linked) together in database 14, via identifier
ID-1 (and, optionally, via ID-5).
[0038] In some instances, user terminal 18 will create additional
derivatives. Take for instance, an example when user terminal 18
enlarges the derivative 001 image, thus creating a new derivative
001a. This new derivative is preferably uniquely identified with a
digital watermark. A process of digitally watermarking a derivative
typically involves removing the original watermark from the
derivative and replacing the watermark with a new unique
identifier. (In an alternative embodiment, the original watermark
is altered, e.g., by changing one or more message bits, to create
the new unique identifier. In another embodiment, a second
watermark is added to the derivative image to complement the first
(or more) watermark. In this case, the first watermark identifies
the original image, and the second watermark identifies the
derivative.). Preferably, upon creating derivative 001a, the
digital watermarking software removes the derivative 001 watermark
(or at least a portion of the watermark, e.g., identifier ID-5)
from the derivative 001 image. Assignees' U.S. application Ser. No.
09/503,881 discusses some techniques for such. Artisans know others
still. Derivative 001a is then embedded with a unique digital
watermark identifier (e.g., ID-10).
[0039] The watermark embedding software can determine an
appropriate identifier in a number of ways. In one embodiment, the
embedding software queries database 14 for an appropriate, or
available, identifier. In another case, embedding software (or user
terminal 18) is assigned a range of identifiers, and an identifier
is chosen from the available range. In still another embodiment,
the embedding software randomly or pseudo-randomly selects the
identifier, or alters a portion of the original image identifier,
e.g., 2-32 bits of the original watermark identifier.
[0040] An image and a watermark identifier are combined to produce
a digitally watermarked image (or derivative image) preferably in
the same format and density as the input image. As an optional
feature, software provides an indicator to signal success or
failure in the watermarking effort. For example, the software can
analyze whether the watermark was embedded, and/or whether the
image contains the same format and density as the original input
image. Upon a failure, user terminal 18 re-embeds the digital
watermark or aborts the process.
[0041] Derivative image 001a is stored in database 14. Related
information can also be stored in database 14. (As discussed above,
database 14 may include a plurality of databases. One such database
may manage images, while another database manages related
information. Preferably, however, the unique identifiers are used
consistently between the plurality of databases to link related
images and information.). Database 14 links derivative 001a with
image 001, derivative 001 and any related information (e.g.,
metadata, comments, files, history, security, etc.). Accordingly,
image ancestry and any related information is efficiently
maintained.
[0042] FIG. 3 is a diagram further illustrating linking images,
derivatives and related information via a unique watermark
identifier. An original image 20 is watermarked with a unique
identifier 22. A first derivative image 24 (e.g., perhaps an
enlarged or cropped image corresponding with area 20a) and a second
derivative 26 (e.g., corresponding to area 20b) are created. Each
of the first derivative 24 and second derivative 26 are encoded
with a unique watermark identifier. The derivative identifiers are
associated with the unique identifier 22 in database 14. Such
linking effectively groups image families together, permitting a
user to gain access to image ancestry. Similarly, related
information can be linked via unique identifier 22. Returning to
FIG. 3, related information 28 corresponding to first derivative 24
are linked to identifier 22. Files 30 corresponding to the original
image 20, as well as files 32 for the second derivative 26, are
likewise linked. Accordingly, entire image families (and related
information) are efficiently maintained by linking via the unique
identifier 22. Of course, files 28 and 30 optionally can be
separately, and respectively, linked to derivatives 24 and 26, via
the derivatives' unique identifiers (e.g., as shown by the dashed
lines in FIG. 3).
[0043] Security and Rewritable Watermarks
[0044] In one embodiment, a watermark provides information related
to a permission level or a security clearance level. Such
information can be reflected in a unique identifier or in a payload
message. Alternatively, the watermark identifier can be used to
interrogate a database to retrieve related security level
requirements. Such security information can be used to regulate
access to images and related information. For example, only users
(or user terminals) having a corresponding permission level or
security clearance are allowed to access the corresponding image.
Suitable software instructions can examine the permission level (or
security clearance) to determine whether a user (or terminal) has
the necessary clearance.
[0045] One aspect of the present invention is to employ
"rewritable" watermarks. A rewritable watermark includes a
watermark of which all or a portion of which may be changed. In a
preferred embodiment, only a portion (e.g., a portion of the
payload) of a watermark is rewritten to update permission levels,
reflect derivative work, etc.
[0046] There are often situations where it is desirable to carry
some form of security access indicator in an image, e.g., via a
digital watermark. The security access indicator defines a level of
security required to view, edit or comment with respect to an
image. Access to the image is then controlled by appropriately
enabled software, which extracts the indicator (or receives the
indicator from a watermark decoder) and determines usage. In one
embodiment, the indicator indicates defines a required level. If a
user's security level is equal to or greater (e.g., as determined
from a password, user terminal identifier, login, linked security
clearance level, etc.) to that carried in a security access
indicator, then a user is allowed access to the image or data. In
another embodiment, a security code may indicate that a particular
user can view the image, but cannot edit or store comments
regarding such.
[0047] Consider the following example. An image "A" is defined to
include an "unclassified" security classification. Image A's
watermark then includes a unique identifier and additional
plural-bits set to a predetermined number, e.g., all set to zero
(or to a predetermined number or pattern). These additional
plural-bits define the unclassified security classification. An
image "B" is a derivative of image A, and has a "secret" security
classification encoded in the plural-bits. Before either image A or
B is opened (or requested) the security level contained within the
watermark is validated against the security level of the individual
requesting access, and permission is only granted to those with
adequate clearance. In one embodiment, local software (e.g.,
executing on a user terminal) validates the security access by
decoding the watermark, extracting the security bits, and comparing
the security bits (or corresponding security level) with the
security clearance of a user (or terminal). In another embodiment,
software running on a central server monitors and validates
security access. Or in another embodiment software associated with
the database regulates the security access.
[0048] Application Interface
[0049] Application interface software, residing on a user terminal,
helps to facilitate communication between image-handling software
and database 14. The interface can be incorporated in such
image-handling software, operate as a plug-in, be integrated with
the operating system, or may even be called by certain operations
(e.g., data retrieval, editing, saving, etc.). Preferably, the
interface generates (or works in connection with) a graphical user
interface (GUI) for a user. The GUI helps to facilitate user login,
data retrieval, and image creation and saving. Creation is defined
broadly to include any alteration to an existing image, or
generation of a new image. Initially, a user is requested to enter
a password or pass code to interact with database 14. After a
successful log in, user access is preferably regulated based on
security clearance. In other embodiments, permission levels or
payment schedules are used to regulate access. An image, and
related metadata, files, etc., should only be accessible when
security access is permitted. In one embodiment, an image is
selected from a directory, and the selected image is examined for
watermarks. A watermark is extracted and security bits are
determined. The security bits are validated against a corresponding
security access allowed for the logged-on user. A user is permitted
to access (e.g., retrieve, open, or edit) the image if she has an
appropriate clearance. In an alternative arrangement, a database is
queried to determine the security level required for all (or a
subset of all) possible images in a directory or list. Only those
images corresponding to the user's security clearance (or
permission) are presented as options to open for the user. Even the
names of the images can be screened from a user if her security
clearance is insufficient.
[0050] The interface also facilitates communication in a normal
image editing and creation processes. Preferably, the interface
will be invoked as part of a saving process.
[0051] The creation process typically involves determining a new
image identifier. As discussed above, there are many ways to
determine an image identifier. In one case, the interface queries
the database 14 to obtain a new image identifier. The retrieved
image identifier is embedded in the newly created image as a
portion of a digital watermark. The embedded image is then saved in
database 14. Optionally, the database will signal that the save
operation has been successfully completed. In the case of
derivatives, the database is preferably updated to indicate that
the new image identifier is related (or linked) to the identifier
of an original image.
[0052] In one embodiment, the above-mentioned steps (e.g.,
creating, watermarking, and saving) are considered a transaction,
e.g., where all of the steps must be carried out for the
transaction to be complete.
[0053] Sentry
[0054] Another aspect of the present invention is a gatekeeper
module. With reference to FIG. 4, a gatekeeper (or "sentry") 42
resides on network terminals 40 and 44. Terminals 40 and 44
communicate, e.g., via a network, direct link, e-mail, etc. Sentry
42 monitors the flow of digital watermarked images and related
information by extracting digital watermark identifiers or embedded
security information from transmitted images. The sentry 42 can
compare extracted information against user (or terminal) security
clearance information. In one embodiment, sentry is an independent
software module, although sentry 42 may be incorporated into other
software components (e.g., applications, operating system, etc.) of
a network terminal 40 and 44. Sentry 42 monitors and controls the
flow of images at various points in a network system. Such activity
is logged (e.g., recorded, stored, etc.) in database 46. To monitor
an image transmitted from user terminal 40 to user terminal 44,
sentry 42a decodes an embedded watermark identifier from an image
to be transferred (step S10, FIG. 5). The identifier, destination
address, and optionally a date/time stamp are communicated to
database 46 (step S12), where such information is recorded as a
data record (or file, log, table, database entry, history, etc.) as
in step S14. Preferably such transmission activity is associated
with the unique identifier of the transferred image.
[0055] Sentry 42 is also gatekeeper in that it analyzes whether a
user's security or permission level is sufficient to receive a
watermarked image into or from a workstation (e.g., whether
terminal 44 can receive the image transmitted from terminal 40).
Sentry 42b preferably includes watermark-decoding software, which
extracts unique identifiers (and any security bits) from watermark
images (step S20, FIG. 6). If the security level of an image is
stored in a database, sentry 42b queries the database with the
identifier to determine the required access level. Or if the
watermark includes security bits, then sentry 42b determines an
access level directly from extracted security bits. Sentry 42b
determines whether the user's security clearance sufficiently
corresponds with the received image's clearance requirements (step
S22). If so, sentry 42b allows terminal 44 to receive and open the
subject image (step S24). If not, sentry 42b denies terminal 44
access to the image (step S26). In either case, sentry 42b
preferably communicates such information to database 46 (step S28).
For example, sentry 42b records whether the image is passed to
terminal 44, or whether the image is denied. (As an optional
function, sentry 42b notifies terminal 42 regarding the delivery
status of the image.).
[0056] Preferably, sentry 42 does not performed the function of
managing the relationship between images and their derivatives, as
this is the function of the file save software associated with the
image editing application. However, in one embodiment, sentry 42 is
combined with an application interface.
[0057] Sentry 42 can be deployed in a number of ways. In one
embodiment, sentry 42 is integrated (or stored, or connected) to a
workstation or server in such a way that all image data must first
pass through the sentry 42. In another embodiment, sentry 42
includes a separate hardware (or hardware/software) device inserted
between a network (or network connection) and a user terminal. As
such, sentry 42 decodes watermarks and intercepts passwords from
image traffic before the user terminal receives the image, or
directly after transmitting an image.
[0058] In another embodiment, e.g., in a TCP/IP environment, a
sentry 42 is deployed as software within a TCP/IP stack in the user
station or server. In yet another embodiment, a sentry is
incorporated in (or called by) an image-handling program's open,
save and close operations.
[0059] When used in connection with a database history or other
record, sentry 42 provides efficient tracking and tracing. Since
the history file reveals each use (and printing, transmission,
etc.) of a watermarked image, the image can be efficiently tracked
as it passes from terminal to terminal, or from database to
terminal, etc.
[0060] Fragile Watermarks
[0061] Some images may include at least two watermarks. A first
watermark includes a unique identifier, as discussed above. This
identifier allows database inquires and association as discussed
above. A second watermark can be applied prior to printing, faxing,
etc. This second watermark preferably includes a so-called fragile
watermark. That is, it is designed to be lost, or to degrade
predictably, when the data set into which it is embedded is
processed in some manner. (Fragile watermark technology is
disclosed, e.g., in application Ser. Nos. 09/234,780, 09/433,104,
09/498,223, 60/198,138, 09/562,516, 09/567,405, 09/625,577,
09/645,779, and 60/232,163.).
[0062] Once an image is printed, it then includes both the first
and second watermarks. If the image is subsequently scanned back
into a digital form, e.g., via a scanner, photocopier, web cam,
digital camera, etc., the fragile watermark is corrupted (or
destroyed) in a foreseeable manner. Printed copies can be tracked
and traced accordingly. For example, a photocopied image is scanned
into a digital form. The first watermark is used to identify the
image and retrieve an image history (e.g., as created by a sentry
or other logging method). Since the fragile watermark is destroyed
(or predictably degraded) in the copy process, the photocopy is
determined to be an unauthorized copy. The history log can be used
to determine which user, or user terminal, printed the copy.
CONCLUSION
[0063] Watermarks can be applied to any data set (e.g., an image,
map, picture, document, etc.) for forensic tracking purposes. This
is particularly useful where several copies of the same data set
are distributed through different channels (e.g., provided to
different users). Each can be "serialized" with a different
identifier, and a record can be kept of which numbered data set was
provided to which distribution channel. Thereafter, if one of the
data sets appears in an unexpected context, it can be tracked back
to the distribution channel from which it originated.
[0064] In an alternative embodiment, with reference to FIG. 1, a
digital watermark embedder is included in aerial platform 11. The
aerial embedder embeds images (e.g., after or during capture) and
relays such to ground station 12. In yet another embodiment, an
image is digitally watermarked downstream from ground station 12,
such as in a user terminal, or an embedder associated with the
databases 14 and/or 15.
[0065] Although not belabored, artisans will understand that the
systems described above can be implemented using a variety of
hardware and software systems. One embodiment employs a computer or
workstation with a large disk library, and capable database
software (such as is available from Microsoft, Oracle, etc.). The
watermarking and database operations can be performed in accordance
with software instructions stored in the disk library or on other
storage media, and executed by a processor in the computer as
needed. (Alternatively, dedicated hardware, or programmable logic
circuits, can be employed for such operations.)
[0066] The various section headings in this application are
provided for the reader's convenience and provide no substantive
limitations. The features found in one section may be readily
combined with those features in another section.
[0067] To provide a comprehensive disclosure without unduly
lengthening this specification, the above-mentioned patents and
patent applications are hereby incorporated by reference. The
particular combinations of elements and features in the
above-detailed embodiments are exemplary only; the interchanging
and substitution of these teachings with other teachings in this
application and the incorporated-by-reference patents/applications
are also contemplated.
[0068] It should be appreciated that the present invention is not
limited to managing satellite and other aerial imagery. Indeed,
other imagery may be managed with the present invention. Also, the
present invention encompasses a "non-secure" type of system. In one
such embodiment, watermark identifiers are used to link images
and/or related information. A security or permission level is not
required in such a system.
[0069] In view of the wide variety of embodiments to which the
principles and features discussed above can be applied, it should
be apparent that the detailed embodiments are illustrative only and
should not be taken as limiting the scope of the invention. Rather,
we claim as our invention all such modifications as may come within
the scope and spirit of the following claims and equivalents
thereof.
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