System and method for digitally marking a file with a removable mark

• US 8,285,995 B2
• Filed: 04/20/2004
• Issued: 10/09/2012
• Est. Priority Date: 04/06/1999
• Status: Expired due to Fees

• Current Assignee: KWAN Software Engineering Incorporated
• Original Assignee: KWAN Software Engineering Incorporated
• Inventors: Kwan, John Man Kwong
• Primary Examiner(s): Patel, Nirav B
• Application Number:
  US10/828,956
• Publication Number:
  US 20040199772A1
• Time in Patent Office: 3,094 Days
• Field of Search: 713/176, 380200-202, 380/210, 382/194, 382/236, 382/245, 382/239, 382/283
• US Class Current: 713/176
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00884 involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm
• CPC Class Codes: H04N 1/32203 Spatial or amplitude domain methods H04N1/32309 takes precedence
• 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 1/32229 with selective or adaptive application of the additional information, e.g. in selected regions of the image H04N1/32213 takes precedence
• CPC Class Codes: H04N 2005/91335 the copy protection signal being a watermark
• CPC Class Codes: H04N 2201/3226 of identification information or the like, e.g. ID code, index, title, part of an image, reduced-size image
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes

Abstract

A system enables encoding of a removable mark into digital data, and decoding of the mark from the digital data. The system comprises an encoder and a decoder. The encoder includes a target area locator for locating in digital data a predetermined pattern of values that represents a flat area, and a marker for modifying values in the flat area to encode a mark into the flat area. The decoder attempts to extract the mark from the digital data. The decoder includes a mark area locator for locating a predetermined pattern of values in digital data, and an unmarker coupled to the mark area locator for examining the values to determine the state of each value and extract an embedded mark from the predetermined pattern of values.

Claims

1. An apparatus for encoding a mark into digital data, the apparatus comprising:

a data receiver to receive an unencoded data of an audio recording, the data receiver comprising an encoder, the encoder comprising;

a target area locator to locate, in the unencoded digital data of the audio recording, using a predetermined pattern, at least two values that represent a flat area by calculating a variability for a selected portion of the unencoded digital data using the predetermined pattern and locating the at least two values that represent the flat area if the calculated variability for the selected portion is less than a predetermined amount;

a marker to modify at least one of the values in the flat area to encode a mark into the flat area of the audio recording; and

a processor coupled to the data receiver, the processor to communicate with the data receiver to create the encoded data of the audio recording.

2. The apparatus of claim 1, wherein the predetermined pattern is a regular pattern.

3. The apparatus of claim 1, wherein the predetermined pattern is an irregular pattern.

4. The apparatus of claim 1, wherein the predetermined pattern identifies a consecutive set of values.

5. The apparatus of claim 1, wherein the marker modifies the at least one value in the flat area to encode a mark into the flat area of the audio recording according to a recognizable amount.

6. The apparatus of claim 5, wherein the marker modifies the values in the flat area to encode a mark into the flat area of the audio recording by adding the recognizable amount to the at least one value.

7. The apparatus of claim 5, wherein the marker modifies the values in the flat area to encode a mark into the flat area of the audio recording by subtracting the recognizable amount from the at least one value.

8. The apparatus of claim 5, wherein the encoder computes the recognizable amount by calculating a function of the variability in the flat area.

9. The apparatus of claim 5, wherein the encoder computes the recognizable amount as a multiple of the variability in the flat area.

10. The apparatus of claim 1, wherein the marker modifies the at least one value in the flat area to provide at least one known peak in the flat area.

11. The apparatus of claim 1, wherein the marker modifies at least two of the values in the digital data to represent a single mark value in the flat area.

12. The apparatus of claim 1, wherein the target area locator locates, in the digital data, using a predetermined pattern, at least two values that represent a second flat area and wherein the marker modifies at least one value in the second flat area to encode the mark into the second flat area.

13. The apparatus of claim 1, wherein the encoder further comprises a format conversion engine to convert a format of the digital data.

14. The apparatus of claim 1, wherein the apparatus is implemented in at least one computer, the at least on computer accessing a memory.

15. The apparatus of claim 1, wherein the apparatus is implemented in a computer.

16. The apparatus of claim 1, wherein the predetermined pattern is one dimensional.

17. The apparatus of claim 1, wherein the predetermined pattern is two dimensional.

18. The apparatus of claim 1, wherein the predetermined pattern is three dimensional.

19. An apparatus for encoding a mark into digital data, the apparatus comprising:

a target area locator to locate, in the unencoded digital data of the audio recording, using a predetermined pattern, at least two values that represent a flat area by calculating a variability for a selected portion of the unencoded digital data using the predetermined pattern and locating the at least two values that represent the flat area if the calculated variability for the selected portion is less than a predetermined amount;

a marker to modify at least one of the values in the flat area to encode a mark into the flat area of the audio recording; and

a processor to communicate with the target area locator.