US 5,987,136 AGranted

Image authentication patterning

AssigneeTrimble Navigation Limited

InventorsJohn F. Schipper, Allan M. Pelley

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Abstract

Apparatus for producing a self-authenticating visual image of a selected view, using a digital image forming means, such as a digital camera, together with a position determining system that provides position information, including location and/or angular orientation and/or time of observation at the time a digital image is formed and/or distance from the camera to a selected object. The digital image of the selected view is presented as an array of pixels with associated pixel values. The position information is incorporated in the digital image by altering selected pixel bit values for a selected authentication pattern P of pixels in a chosen subset CS of the pixel array; and this selected pattern may be determined using the position information. The position information may be encrypted, using an encryption key based on position information, and may be stored separate from, or as part of, the digital image. The authentication pattern is represented by an authentication key or indicium, a single number or an ordered sequence of numbers, that is transmitted with the modified digital image and incorporated position information. The authentication pattern P is preferably chosen so that any circle or other connected pixel region of diameter at least equal to a selected number D contains at least one pixel from the subset CS. The pixel array may be overlaid by a set of polygons, such as triangles, rectangles, parallelograms or hexagons, with at least one pixel from the subset CS in each polygon.

Claims30

Dependent claims

Apparatus for producing a self-authenticating image, the apparatus comprising:

a digital image camera, including a digital image-forming lens that forms a digitally expressed image ("digital image") of a selected view as an array of pixel values, with each pixel value corresponding to a pixel in an array of pixels;
a position determination mechanism, including a digital computer, for determining position information that includes at least one of the location of the digital camera, the angular orientation of the digital camera, the time a digital image is formed, and an estimated distance from a selected object to the digital image camera, at the time the digital image camera forms a digitally image;
digital image storage means for receiving a digital image from the digital image camera, for receiving the position information from the position determination mechanism, for combining the digital image with the position information to form a modified digital image in which each pixel value in a chosen subset CS of the array of pixels is reformed as a modified pixel value to contain a portion of the position information, for storing the modified array of pixel values, and for providing an authentication indicium that indicates the chosen subset CS of the modified array of pixels;
and
an authentication mechanism, connected to the digital image storage means, for receiving putative position information for a selected digital image, for using the authentication indicium to retrieve the position information from the digital image storage mechanism, for comparing the putative position information with the retrieved position information, and for taking at least one of the following actions:
(i) withholding authentication of the selected digital image if the putative position information does not substantially agree with the retrieved position information and (ii) authenticating the selected digital image if the putative position information substantially agrees with the retrieved position information.

3 more elements

A method for producing a self-authenticating digital image, the method comprising the steps of:

forming a digitally expressed image of a selected view as an array of pixel values, using a digital camera, with each pixel value corresponding to a pixel in an array of pixels;
determining position information that includes at least one of the location of the digital camera, the angular orientation of the digital camera and the time at which a digital image was formed;
receiving a selected digital image from the digital camera;
receiving the position information for the digital image;
combining the digital image with the position information to form a modified digital image in which each pixel value in a chosen subset CS of the array of pixels is reformed as a modified pixel value array to contain a portion of the position information, and storing the modified pixel value array in a digital image storage mechanism;
and
providing an authentication indicium that indicates the chosen subset CS of the array of modified pixel values;
receiving putative position information for a selected digital image;
using the authentication indicium to retrieve the position information from the digital image storage mechanism;
comparing the putative position information with the retrieved position information;
and
taking at least one of the following actions:
(i) withholding authentication of the selected digital image if the putative position information does not substantially agree with the retrieved position information and (ii) authenticating the selected digital image if the putative position information substantially agrees with the retrieved position information.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/991,314Filed 16 Dec 1997 · continuation
Priority: 4 Aug 1997
Granted: 16 Nov 1999
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

H04N 1/32203
Methods relating to embedding, encoding, decoding, detection or retrieval operations: spatial or amplitude domain methods
G01S 19/53
The satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting…:…
G01S 17/86
Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems: combinations of lidar systems…
H04N 2101/00
Still video cameras