Information hiding in stationary images

1. Information hiding instationaryimages staffcorporal Piotr Lenarczyk MilitaryUniwersity of Technology Institute of Electronics and Telecomunication

2. Watermarking „Digital image watermarking means embedding information into image in such a way that it is imperceptible to a human observer, but can be easily detected by special computer algorithm.” Ingemar J. Cox

3. Applications of watermarking • Owner Identification • Proof of Ownership • Copy Control • Device Control • Broadcast Monitoring • Content Authentication

4. Method of changing Discrete Cosine Transform coefficients in frueqency domain

5. 2-Dimensional DiscreteCosineTransform DCT 2D M,N = 8 m,n – discrete index of pixel position k,l discrete index of DCT coefficient

6. DCT 2D Basis Functions Q= Basis functions matrices of Discrete Cosine Transform for block 8x8 pix 2 dimensional Discrete Cosine Transform coefficients Standard quantization matrix used in JPEG algorithm

7. A = Matrix A represents block of 8 x 8 pixel values Original image 0,55 23,55 B = Matrix B represents DCT 2D calculated on matrix A: Watermarked image

8. Perceptualtransparency Robustness Data payload

9. Original picture Watermarked picture for scalling coefficient k=23 Watermarked picture for scalling coefficient k=3000

10. BCH code influence on Bit Error Rate

12. Thankyou for yourattention. Questions?