Geographically watermarked imagery and methods

• US 20020135600A1
• Filed: 11/28/2001
• Published: 09/26/2002
• Est. Priority Date: 03/05/2001
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B.
• Granted Patent: US 6,950,519 B2
• Time in Patent Office: Days
• US Class Current: 345/629
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking
• 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 2201/3204 of data relating to a user, sender, addressee, machine or electronic recording medium H04N2201/3256 and subgroups take precedence
• CPC Class Codes: H04N 2201/3252 Image capture parameters, e.g. resolution, illumination conditions, orientation of the image capture device H04N2201/3256 and subgroups take precedence
• CPC Class Codes: H04N 2201/3253 Position information, e.g. geographical position at time of capture, GPS data
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3284 for error correction

Abstract

An image is digitally watermarked to convey position data about the subject of the image, such as latitude, longitude and elevation of a point depicted therein. Additional information, e.g., about camera attributes, camera angle, and 3D warp-characterizing polynomial coefficients, can also be included.

Claims

1. A method comprising digitally watermarking an image with a payload that represents at least two position coordinates for a point depicted within the image.

2. The method of claim 1 in which the payload additionally represents at least one of the following:

(a) the direction of a vector extending from said image to a known compass point;

(b) a scale datum, relating a span of pixels in the image to a span of terrain depicted in the image;

(c) a polynomial tending to characterize an apparent warp of the image.

3. The method of claim 2 in which the payload represents the direction of a vector extending from said image to a known compass point.

4. The method of claim 2 in which the payload represents a scale datum, relating a span of pixels in the image to a span of terrain depicted in the image.

5. The method of claim 2 in which the payload represents a polynomial tending to characterize an apparent warp of the image.

6. The method of claim 1 in which said position coordinates include latitude and longitude.

7. A method comprising digitally watermarking an image with a payload that includes first and second portions, said watermarking using a tiled approach, wherein uniformly-sized patches of the image are processed in accordance with the payload, wherein the first portion is unchanging across all of said tiles, but the second portion changes between tiles, so that position information about each tile can be determined therefrom.

8. A method comprising digitally watermarking different regions of an image with different watermark payload data, wherein a first region of the image is watermarked with payload data relating to an elevation of terrain depicted in said first region, and a second region of the image is watermarked with payload data relating to an elevation of terrain depicted in said second region.

9. The method of claim 8 wherein both of said first and second regions are watermarked with payload data that represents latitude and longitude of a point depicted within said image.