Verification of images captured using a timestamp decoded from illumination from a modulated light source

• US 10,074,030 B2
• Filed: 04/28/2015
• Issued: 09/11/2018
• Est. Priority Date: 05/12/2014
• Status: Expired due to Fees

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Philips Lighting BV (Koninklijke Philips N.V.)
• Inventors: Van Eeuwijk, Alexander Henricus Waltherus, Chelton, William Nathan
• Primary Examiner(s): PRABHAKHER, PRITHAM DAVID
• Application Number:
  US15/311,160
• Publication Number:
  US 20170124421A1
• Time in Patent Office: 1,232 Days
• Field of Search: 3482221
• CPC Class Codes: G06F 21/602 Providing cryptographic facilities or services
• CPC Class Codes: G06F 2221/2151 Time stamp
• CPC Class Codes: G06V 40/172 Classification, e.g. identification
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H04N 1/32128 attached to the image data, e.g. file header, transmitted message header, information on the same page or in the same computer file as the image for information embedded in the image H04N1/32144
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 1/32208 involving changing the magnitude of selected pixels, e.g. overlay of information or super-imposition H04N1/32219, H04N1/32224 take precedence
• CPC Class Codes: H04N 1/32251 in multilevel data, e.g. greyscale or continuous tone data
• CPC Class Codes: H04N 1/32309 in colour image data
• CPC Class Codes: H04N 2201/0084 Digital still camera
• CPC Class Codes: H04N 2201/3205 of identification information, e.g. name or ID code H04N2201/3209 takes precedence
• CPC Class Codes: H04N 2201/3214 of a date
• CPC Class Codes: H04N 2201/3215 of a time or duration
• CPC Class Codes: H04N 2201/3235 Checking or certification of the authentication information, e.g. by comparison with data stored independently
• CPC Class Codes: H04N 2201/3253 Position information, e.g. geographical position at time of capture, GPS data
• CPC Class Codes: H04N 2201/3273 Display
• CPC Class Codes: H04N 2201/3281 Encryption; Ciphering
• CPC Class Codes: H04N 23/56 provided with illuminating means

Abstract

A device comprising: an input for receiving images captured by a camera, of an environment illuminated by light from a light source; an image processing module; and a verification module. The image processing module is configured to process one or more of the images to decode a timestamp modulated into the light, and to output an indication of the decoded timestamp. The verification module is arranged to receive the indication of the decoded timestamp output by the image processing module, and based thereon to perform an at least partially automated verification of a time at which the one or more images were captured.

Claims

1. A device comprising:

an input for receiving images captured by a camera, of an environment illuminated by light from a visible light source;

an image processing module configured to process one or more of the images to decode a timestamp modulated into said light, and to output an indication of the decoded timestamp; and

a verification module arranged to receive the indication of the decoded timestamp output by the image processing module, and based thereon to perform an at least partially automated verification of a time at which the one or more images were captured by comparing the timestamp as currently decoded from said image with a previously determined version of the timestamp;

wherein the image processing module is further configured to apply a facial recognition and/or other image recognition algorithm to at least one of the captured images, and to thereby identify a person or persons appearing in the at least one image.

2. The device of claim 1, wherein the image processing module is further configured to decode, from the processing of the one or more images, information modulated into the light indicative of a location of the light source or environment, and to output an indication of the location for verification of a location at which the one or more images were captured.

3. The device of claim 2, wherein said information comprises:

coordinates or a name of the location explicitly encoded into the light;

or

an identifier of the light source that is mapped to a location in a location database, the image processing module being configured to look up the location from the location database based on said identifier.

4. The device of claim 1, wherein the timestamp is cryptographically secured, and the image processing module is configured to use a cryptographic key to access the timestamp.

5. The device of claim 1, wherein:

the image processing module is configured to store the one or more images in at least one image file, wherein said outputting comprises storing the decoded timestamp in the image file as metadata of the image file, said previously determined version of the timestamp being the stored decoded timestamp;

the image processing module is configured to decode the timestamp again later from the one or more stored images; and

the verification module is configured to perform said at-least-partially automated verification by comparing the later decoded timestamp with the stored timestamp in the metadata in order to verify the stored timestamp.

6. The device of claim 5 wherein the timestamp in the metadata or the metadata as a whole is cryptographically secured, and the verification module is configured to use a cryptographic key to access the timestamp or metadata.

7. The device of claim 1, wherein the camera adds its own timestamp to at least one of said one or more the images, said previously determined version of the timestamp being the camera'"'"'s timestamp, and the verification module is configured to perform said at-least-partially automated verification by comparing the camera'"'"'s own timestamp with the decoded timestamp in order to verify the camera'"'"'s timestamp.

8. The device of claim 1, wherein the timestamp as modulated into said light is signed using a private key, and the verification module is configured to perform said at least-partially-automated verification by verifying the decoded timestamp using a corresponding public key.

9. The device of claim 1, wherein the image processing module is configured to remove the modulation from said one or more images once the timestamp has been decoded, stored or verified.

10. An image capturing system comprising:

the device of claim 1;

the light source, being arranged to emit light to illuminate said environment, and configured to modulate the light emitted by the light source with said timestamp indicating a current time value; and

the camera, being arranged to capture said one or more images of said environment.

11. A computer program product for processing images, the computer program product comprising code embodied on a non-transitory computer-readable storage medium and configured so as when executed to perform operations of:

receiving images captured by a camera, of an environment illuminated by light from a light source; and

processing one or more of the images to decode a timestamp modulated into said light indicating a time at which the one or more images were captured;

based on the timestamp as determined by said processing, performing an at least partially automated verification of the time at which the one or more images were captured by comparing the timestamp as currently decoded from said image with a previously determined version of the timestamp; and

apply a facial recognition and/or other image recognition algorithm to at least one of the captured images, and to thereby identify a person or persons appearing in the at least one image.

12. The computer program product of claim 11, wherein the computer program product is further configured to:

decode, from the processing of the one or more images, information modulated into the light indicative of a location of the light source or environment, and to output an indication of the location for verification of a location at which the one or more images were captured; and

log the fact that the identified person or the identified persons are verified to have been at said location at said time.

13. The computer program product of claim 12, wherein said logging comprises logging said fact as part of one or more of:

a location-based game,

a retail rewards scheme,

a social networking system, and/or

a celebrity spotting application.

14. A method comprising:

using light emitted from a light source to illuminate an environment;

encoding a timestamp indicating a current time value into the light emitted by the light source;

using a camera to capture one or more of said environment;

processing at least one of the images to determine the timestamp encoded into said light; and

based on the timestamp as determined by said processing, performing an at least partially automated verification of a time at which the at least one image was captured by comparing the timestamp as currently decoded from said image with a previously determined version of the timestamp; and

applying a facial recognition and/or other image recognition algorithm to at least one of the captured images, and to thereby identify a person or persons appearing in the at least one image.