1 / 18

Hidden Digital Watermarks in Images

Hidden Digital Watermarks in Images. Chiou-Ting Hsu and Ja-Ling Wu, Senior Member, IEEE IEEE TRANSACTIONS ON IMAGE PROCESSING, VOL. 8, NO. 1, JANUARY 1999, pp. 58 -68 Adviser : Dr. Chang, Chin-Chen Reporter : Huang, Chang-Chin Date : 2003/04/22. Outline. INTRODUCTION

kellyhayes
Télécharger la présentation

Hidden Digital Watermarks in Images

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hidden Digital Watermarks in Images Chiou-Ting Hsu and Ja-Ling Wu, Senior Member, IEEE IEEE TRANSACTIONS ON IMAGE PROCESSING, VOL. 8, NO. 1, JANUARY 1999, pp. 58 -68 Adviser : Dr. Chang, Chin-Chen Reporter : Huang, Chang-Chin Date : 2003/04/22

  2. Outline • INTRODUCTION • EMBEDDING METHODS • WATERMARK EXTRACTING METHOD • EXPERIMENTAL RESULTS • CONCLUSION

  3. INTRODUCTION • resistant to lossy data compression, e.g., the Joint Photographic Experts Group (JPEG) compression; • resistant to image manipulation and processing operations, e.g., cut-and-paste, filtering, etc.

  4. EMBEDDING METHODS Ir C D E1 O1 F2 E2 A B GO TO WATERMARK EXTRACTING F1 Wr

  5. EMBEDDING METHODS (A)Pseudorandom Permutation of the Watermark • First：number each pixel from zero to (M1 * M2). • Second：generate each number in random order. • Finally：generate the coordinate pairs by mapping the random sequence number into a 2-D sequence. Return Embedding

  6. EMBEDDING METHODS (B)Block-Based Image-Dependent Permutation of the Watermark block (i,j) is shuffled to block (k,l) by the block-based permutation Wp Wb Wp Wb Return Embedding

  7. EMBEDDING METHODS (C)Block Transformation of the Image Y=FDCT(X) [forward DCT] 1. RGBYCbCr Y = 0.2990R + 0.5870G + 0.1140B Cb =-0.1687R - 0.3313G + 0.5000B Cr = 0.5000R - 0.4187G - 0.0813B 2. DCT Transfer Return Embedding

  8. EMBEDDING METHODS (D)Choice of Middle-Frequency Coefficients Return Embedding

  9. EMBEDDING METHODS (E1)Modification of the DCT Coefficients • binary polarity pattern • reverse the corresponding polarity Return Embedding

  10. EMBEDDING METHODS (E2)Modification of the DCT Coefficients • Luminance quantization table • polarity Return Embedding

  11. EMBEDDING METHODS (F1)Inverse Block Transform map the modified middle-frequency coefficients into Y to get Return Embedding

  12. EMBEDDING METHODS (F2)Inverse Block Transform inverse DCT (IDCT) of the associatedresult to obtained the embedded image = IDCT( ) Return Embedding

  13. WATERMARK EXTRACTING METHOD Ir O1 Wr GO TO WATERMARK EMBEDDING

  14. EXPERIMENTAL RESULTS 1

  15. EXPERIMENTAL RESULTS 2

  16. EXPERIMENTAL RESULTS 3

  17. EXPERIMENTAL RESULTS 4

  18. CONCLUSION • image resampling and image rotation, are still challenging to our current work.

More Related