張真誠 逢甲大學 講座教授 中正大學 榮譽教授 清華大學 合聘教授

Presentation on theme: "張真誠 逢甲大學 講座教授 中正大學 榮譽教授 清華大學 合聘教授"— Presentation transcript:

1 張真誠 逢甲大學 講座教授 中正大學 榮譽教授 清華大學 合聘教授
影像偽裝術的最新發展 張真誠 逢甲大學 講座教授 中正大學 榮譽教授 清華大學 合聘教授

2 Watermarking Image authentication Secret sharing Visual cryptography Steganography

3 Watermarking Visible watermarking Easy to embed Clear to see watermark

4 Watermarking (Cont.) Invisible watermarking Requirements:
Good visual quality of watermarked image Robustness Watermarking Original image Watermarked image Watermark

5 Image authentication Requirements: Detect the tampered area
Try to restore the tampered area Image Tampered image Detected image Restored image

6 Secret sharing Classification: Meaningless shadows Meaningful shadows

7 Secret sharing (Cont.) Sharing Shadow size: 256  256 Reconstructing
Image size: 512  512 Reconstructing (2,4)-threshold secret sharing scheme PSNR=24 dB

8 Secret sharing (Cont.) Reconstructing Secret image Hiding Stego-image
Reconstructed secret image Secret image Stego-image (2, n)-threshold secret sharing scheme Stego-image

9 Visual cryptography Stacking Shadow 1 Shadow 2 Secret

10 Visual cryptography (Cont.)
Stacking Shadow 1 Shadow 2 Secret

11 Visual cryptography (Cont.)
Rotating 40o Stacking Stacking Share 1 Share 2 Secret 1 “VISUAL” Secret 2 “SECRET”

12 Steganography The targets Restoration
Frequency domain (e.g. DCT, DWT, DFT) Spatial domain (e.g. pixel values) Compression domain (e.g. VQ) Text Restoration Irreversible Reversible

13 Steganography (Cont.) Image Hiding system Stego image Cover image
Secret message Stego image

14 Steganography (Cont.) Text Video Sound 壞的毛病 壞毛病 山東的蘋果 山東蘋果 我的媽媽 我媽媽
壞的毛病 壞毛病 山東的蘋果 山東蘋果 我的媽媽 我媽媽 主要的問題 主要問題 另外的一件事 另外一件事 其他的問題 其他問題 北京的大學 北京大學 Video Sound

15 Zhang and Wang’s Method (Embedding)
8 7 9 4 79 54 55 11 20 21 12 24 10 Secret data: … p2 255 1 2 3 4 1 2 3 4 1 : : : : : : : : : : : : : 10002 1 35 … 11 2 3 4 1 2 3 4 1 2 3 2 … 10 1 2 3 4 1 2 3 4 1 Cover image … 9 3 4 1 2 3 4 1 2 3 4 3 … 8 1 2 3 4 1 2 3 4 1 2 1 … 7 4 1 2 3 4 1 2 3 4 4 … 6 2 3 4 1 2 3 4 1 2 3 2 … 5 1 2 3 4 1 2 3 4 1 7 10 4 … 4 3 4 1 2 3 4 1 2 3 4 3 … 3 1 2 3 4 1 2 3 4 1 2 1 … 2 4 1 2 3 4 1 2 3 4 4 … 1 2 3 4 1 2 3 4 1 2 3 2 … 1 2 3 4 1 2 3 4 1 Stego image 1 2 3 4 5 6 7 8 9 10 11 … 255 p1 Magic Matrix

16 Zhang and Wang’s Method (Extracting)
p2 7 10 4 255 1 2 3 4 1 2 3 4 1 : : : : : : : : : : : : : … 11 2 3 4 1 2 3 4 1 2 3 2 … 10 1 2 3 4 1 2 3 4 1 … 9 3 4 1 2 3 4 1 2 3 4 3 … 8 1 2 3 4 1 2 3 4 1 2 1 Stego image … 7 4 1 2 3 4 1 2 3 4 4 … 6 2 3 4 1 2 3 4 1 2 3 2 … 5 1 2 3 4 1 2 3 4 1 … 4 3 4 1 2 3 4 1 2 3 4 3 … 3 1 2 3 4 1 2 3 4 1 2 1 … 2 4 1 2 3 4 1 2 3 4 4 1 35 … 1 2 3 4 1 2 3 4 1 2 3 2 … 1 2 3 4 1 2 3 4 1 p1 1 2 3 4 5 6 7 8 9 10 11 … 255 Extracted secret data: 10002 Magic Matrix

17 Sudoku A logic-based number placement puzzle

18 Sudoku (Cont.) Property
A Sudoku grid contains nine 3 × 3 matrices, each contains different digits from 1 to 9. Each row and each column of a Sudoku grid also contain different digits from 1 to 9. Possible solutions: 6,670,903,752,021,072,936,960 (i.e. ≈ 6.671×1021)

19 Data Hiding Using Sudoku
- 1 Reference Matrix M

20 Data Hiding Using Sudoku (Embedding) (Cont.)
8 7 11 12 79 54 55 20 21 24 10 9 Secret data: … 279 Cover Image min. d( , ) = ((8-8)2+(4-7)2)1/2=3 d( , ) = ((9-8)2+(7-7)2)1/2=1 d( , ) = ((6-8)2+(8-7)2)1/2=2.24 9 7 Stego Image

21 Data Hiding Using Sudoku (Embedding) (Cont.)
8 7 11 12 79 54 55 20 21 24 10 9 Secret data: … 279 Cover Image d( , ) = ((11-11)2+(15-12)2)1/2=3 d( , ) = ((15-11)2+(12-12)2)1/2=4 d( , ) = ((9-11)2+(14-12)2)1/2=2.83 min. 9 7 14 Stego Image

22 Data Hiding Using Sudoku (Extracting) (Cont.)
9 7 14 Stego Image Extracted data: 279 =

23 Experimental Results

24 Experimental Results (Cont.)
The results of visual quality and Embedding capacity comparisons Images Proposed PSNR C Baboon Barbara Boats Goldhill Jet(F16) Lena Pepper Sailboat Tiffany 44.68 44.77 44.94 44.84 45.02 44.97 44.67 1.5 Average 44.88