System and method for data hiding in compressed fingerprint images

• US 6,301,368 B1
• Filed: 01/29/1999
• Issued: 10/09/2001
• Est. Priority Date: 01/29/1999
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ratha, Nalini Kanta, Bolle, Rudolf Maarten, Connell, Jonathan Hudson
• Primary Examiner(s): Johns, Andrew W.
• Assistant Examiner(s): NAKHJAVAN, SHERVIN K
• Application Number:
  US09/240,446
• Time in Patent Office: 984 Days
• Field of Search: 382/100, 382/232, 382/246, 382/251, 382/276, 382/282, 382/284, 713/176, 713/179, 705/64, 705/67, 455/411, 380/258, 348/568, 707/101
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0053 Embedding of the watermark in the coding stream, possibly without decoding; Embedding of the watermark in the compressed domain
• CPC Class Codes: H04N 1/32154 Transform domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/3217 using wavelet transforms
• CPC Class Codes: H04N 1/32187 with selective or adaptive application of the additional information, e.g. in selected frequency coefficients
• CPC Class Codes: H04N 1/32277 Compression
• 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
• CPC Class Codes: H04N 2201/3278 Transmission
• CPC Class Codes: H04N 2201/3283 Compression

Abstract

A method to hide small messages in a wavelet compressed fingerprint image is presented. The method is characterized by random placement of the message bits in the compressed and quantized indices. The compressed image can be decompressed by any certified decompressor without any visible difference. However, the decoder aware of the decompression can only retrieve the hidden message in the image and additionally decompress the image without any error in pixel values.

Claims

1. A computer system for hiding an information sequence in a compressed image comprising:

an image compressor that spatially compresses an image to create a spatially compressed image with a plurality of frequency components, each with a respective spatial frequency and a respective amplitude;

a candidate selector that selects a selected set of a plurality of the frequency components, the selected set having the frequency components with high spatial frequencies and large amplitudes;

a data site selector that uses a random process to randomly select from the selected set to create a site set; and

a site modifier that partitions the information sequence into one or more portions and uses one or more of the portions to modify one of the amplitudes of one of the frequency components in the site set.

2. A computer system, as in claim 1, where the image compressor is any one or more of the following:

a wavelet scalar quantization (WSQ), a joint picture expert group (JPEG), a motion picture expert group (MPEG), JBIG, or other frequency decomposition compression scheme.

3. A computer system, as in claim 1, where the image is any one or more of the following:

a fingerprint image, a face image, a biometric signature, or other biometrics signals.

4. A computer system, as in claim 1, where the frequency component has a high spatial frequency when the frequency is large compared to the smallest frequency subband used in the compression algorithm.

5. A computer system, as in claim 1, where the frequency component has a high spatial frequency when the frequency is at least two times higher than the lowest frequency subband used in the compression algorithm.

6. A computer system, as in claim 1, where the frequency component has a large amplitude when the contribution of the least significant portion is small compared to the magnitude of the amplitude of the frequency component.

7. A computer system, as in claim 1, where the frequency component has a large amplitude when the contribution of the least significant portion is five times smaller than the magnitude of the amplitude of the frequency component.

8. A computer system, as in claim 1, where the random process includes any one or more of the following:

a pseudo-random number generator, an algorithm to select the seed for the pseudo-random generator, a modulus.

9. A computer system, as in claim 8, where a portion of the pseudo-random number generator seed is computed from the frequency components of the spatially compressed image.

10. A computer system, as in claim 1, where the information sequence includes any one or more of the following:

a text stream, a user identification number, a date, a time, a social security number, a serial number, global positioning system reported coordinates.

11. A computer system, as in claim 1, where the portions include any one or more of the following:

bits, nibbles, bytes, characters, fixed size subdivisions or variable sized subdivision of the information sequence.

12. A computer system, as in claim 1, where the site modifier uses any one or more of the following to modify the amplitude:

a logical function of the portion, a random function of the portion, a strictly monotonic function of the portion.

13. A computer system, as in claim 1, where the site modifier stores portions of the amplitudes before they are modified in a data appendage that is appended to the compressed image.

14. A computer system, as in claim 1, where the site modifier stores restoration information about how to restore the modified amplitudes in a data appendage that is appended to the compressed image.

15. A computer system for extracting a hidden information sequence from a compressed image comprising:

an image decompressor that partially decompresses the image to create a plurality of frequency components, each with a respective spatial frequency and a respective amplitude;

a candidate selector that selects a selected set of a plurality of the frequency components, the selected set having the frequency components with high spatial frequencies and large amplitudes;

a data site selector that uses a random process to randomly select from the selected set to create a site set; and

a message extractor that uses one of the amplitudes of one of the frequency components in the site set to extract one or more portions of the information sequence.

16. A computer system, as in claim 15, where the message extractor uses any one or more of the following:

a logical function of the amplitude, a random function of the amplitude, a strictly monotonic function of the amplitude.

17. A computer system, as in claim 15, where the message extractor restores the portions of the amplitudes from a data appendage that is appended to the compressed image.

18. A computer system, as in claim 15, where the message extractor restores the amplitudes using restoration information from a data appendage that is appended to the compressed image.