Presentation on theme: "1 Self-Recovery Fragile Watermarking Scheme with Variable Watermark Payload Fan Chen, Hong-Jie He, Yaoran Huo, Hongxia Wang Southwest Jiaotong University,"— Presentation transcript:
1 Self-Recovery Fragile Watermarking Scheme with Variable Watermark Payload Fan Chen, Hong-Jie He, Yaoran Huo, Hongxia Wang Southwest Jiaotong University, Chengdu, Sichuan, P.R. China
2 Fan Chen Chengdu, Sichuan, China Southwest Jiaotong University An associate professor, and pursuing the Ph.D degree Research interests: digital watermarking and Digital-forensics.
3 Presentation Outline 1.Background 2.Proposed Self-recovery Scheme 3.Experimental Results 4.Conclusions and Future Work Self-Recovery Fragile Watermarking Scheme with Variable Watermark Payload
4 1. Background Image Blocks Block codes ： 8×8 pixels: DCT coefficients 2×2 pixels : average intensity Common Characteristic The length of block codes is fixed.
5 5 1. Background SIP laboratory Examples: Smooth Rough Blocks DCT quantized coefficients . Z.Qian et al, Image self-embedding with high-quaility restoration capability, Digital Signal Processing, 21 (2011): 278-286.
6 6 1. Background SIP laboratory Qian  proposed that the blocks were encoded to different number of bits. The rougher blocks have more bits And the smoother blocks have fewer bits. But, the amount of the compression code bits was still fixed for different images, no matter the image is smooth or rough. . Z.Qian et al, Image self-embedding with high-quaility restoration capability, Digital Signal Processing, 21 (2011): 278-286.
7 The watermark payload is more than the average length of the codes. This is due to the following two facts: Tampering coincidence problem: Dual watermark , Reference Sharing Mechanism  Tamper detection problem: Authentication data Increasing watermark payload Decreasing the quality of watermarked image Being vulnerable to the collage attack 1. Background
8 2 The Proposed Scheme Main purpose Reducing the watermark payload as much as possible while maintaining good recovery quality and security Strategies Variable watermark payload
10 Variable-Length Block Coding For a block of 8×8 pixels: The basic-code: 24 bit The total-code : the number of bits is variable 2 The Proposed Scheme -----watermarked Image Generation Type sType-code Code length v i (bits) 100127 201043 301158 410070 510185 6110101 Code length: (24+27,24+101)
11 Variable-Payload Watermark Insertion 1.Watermark payload equals to the length of block-codes. 2.Basic-code and total-code of a block are encrypted and hidden in the different blocks based on secret key. 2 The Proposed Scheme -----watermarked Image Generation
12 2 The Proposed Scheme -----Watermarked Image Generation Basic-code Total-code Basic-code: the second LSB of the last 24 pixels Total-code
13 SIP laboratory Tamper Detection: Statistical Detection  (1) Basic-code mapping: T B (2) Total-code mapping : T T (3) Incorporation : T 2 The Proposed Scheme -----Watermarked Image Generation
14 SIP laboratory Basic-code matching Total-code matching Detection results T Tamper detection performance is better  He ea al, Adjacent-Block Based Statistical Detection Method for Self- Embedding Watermarking Techniques, 2009 2 The Proposed Scheme -----Watermarked Image Generation
15 Tamper Recovery : Only for the invalid blocks. Watermark-reserved: the tampered block whose basic-code or total-code is valid the corresponding codes Watermark-destroyed: the tampered block whose basic-code and total-code are destroyed the valid blocks adjacent to the block 2 The Proposed Scheme ----- Tamper Detection and Recovery
16 3. Experimental results Images Watermark Payload (bpp) Proposed Qian Invisibility (dB) Proposed Qian  Boat1.35346.4937.92 Lena1.46346.1637.94 Airplane1.47346.0237.93 Barbara1.63345.4137.87 Mona Lisa1.63345.7037.97 Elaine1.64345.5237.94 Goldhill1.73345.1237.93 Napoleon1.74345.0637.96 Man1.77345.0237.93 Fingerprint1.95344.3637.79 The watermark payload and invisibility for different images
17 Restoration Performance The tampered image can be recovered by the proposed scheme with an acceptable visual quality even the tamper ratio is up to 60% of the host image. 3. Experimental results
18 (a) Watermarked Napoleon (b) Watermarked Mona Lisa Collage attack 3. Experimental results both of size 372×288