Information hiding method with reduced fuzziness

• US 6,859,545 B1
• Filed: 08/10/2000
• Issued: 02/22/2005
• Est. Priority Date: 08/10/2000
• Status: Active Grant

• Current Assignee: National Chung-Shan Institute of Science and Technology
• Original Assignee: Chung-Shan Institute of Science & Technology Armaments Bureau MND (Government of The Republic of China)
• Inventors: Wu, Kuang-Shyr
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): EDWARDS, PATRICK L
• Application Number:
  US09/639,674
• Time in Patent Office: 1,657 Days
• Field of Search: 382/100, 382/232, 380/54, 358/3.28
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0057 Compression invariant watermarking
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0083 whereby only watermarked image required at decoder, e.g. source-based, blind, oblivious

Abstract

An information hiding method with reduced fuzziness, which employs interleaving encoding, convolutional encoding and contrasts among neighboring pixels. Once the information is hidden, it can still be extracted without the original image from the generated image after a certain extent of fuzziness damage.

Claims

1. An information hiding method with reduced fuzziness, which comprises the steps of:

inputting the information to be embedded into a convolutional encoder and generating encoded information whose length is a multiple of the original information;

generating a random number sequence using interleaving encoding for permuting the encoded information, the seed of the random numbers being a first key;

selecting a pixel of a host image using a random number generator as an information embedding point of the encoded information, the seed of the random number generator being a second key, and

embedding the encoded information into a B channel of the pixel of the host image;

further wherein the host image H is an image of m×

n pixels and the electronic signature to be embedded is information W with a size L, both the host image H and the embedded information W being expressed as;

H={h_ij|0≦

i<

m,0≦

j<

n, h_ij ε

[0,255]}, and

W={w_i|0≦

L, w_i ε

[0,1]}; and

a set ASET_ij={h_i+lj, h<sub>i−

lj+1</sub>, h_ij+1, h_i+lj+1} being defined for four pixels surrounding and to the right of any pixel h_ij in the host image.

2. The method according to claim 1, wherein the convolutional encoding corrects transmission errors or human damages on the encoded information.

3. The method according to claim 1, wherein the random number sequence is generated by a linear feedback shift register.

4. The method according to claim 3, wherein the linear feedback shift register comprises a plurality of buffers.

5. The method according to claim 1 further comprising the following steps for extracting the embedded information:

using the second key to compute the embedding positions of the encoded information;

using the first key to reconstruct the encoded information and to restore the order before interleaving encoding; and

decoding the encoded information using convolutional decoding.

6. The method according to claim 1, wherein a temporary variable is defined to be h′

=(h<sub>i−

lj−

1</sub>+h<sub>ij−

1</sub>+h<sub>i−

lj+1</sub>+h<sub>i−

lj</sub>+h_i+lj+h<sub>i−

j+1</sub>+h_ij+1+h_i+lj+1)/8.

7. The method according to claim 5, wherein the hidden information is true is h□

h_ij in the step of using the second key to compute the embedding positions of the encoded information.

8. The method according to claim 5, wherein the convolutional decoding adopts the Viterbi algorithm.