Watermarking in-imageprocessing

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Watermarking in-imageprocessing

  1. 1. Digital Water Marking By Sheikh Qaisar Ayub Advanced Topics in Image Processing [email_address] Qaisar Ayub & Sulma Rashid
  2. 2. Watermark Observe image It is intellectual property Some one may spend a lot of time And thinking to compose this image
  3. 3. The image has been extended by any other person now he is owner of image
  4. 4. How to protect image ? P roblem Solution Watermark
  5. 5. <ul><li>What ? </li></ul><ul><li>The term watermark is derived from the German term “Wessmark” </li></ul><ul><li>Basic Idea </li></ul><ul><li>The basic idea of watermark is to embed some information in digital </li></ul><ul><li>images so that it can not be miss used or owned by others </li></ul>Watermarked image Image without watermark Watermark
  6. 6. <ul><li>Visible watermark </li></ul><ul><li>The visible watermark consist of visible message of company logo </li></ul><ul><li>indicating the ownership of image. </li></ul>Watermark
  7. 7. <ul><li>Visible watermark </li></ul><ul><li>The implementation of visible watermarks can be applied in following areas </li></ul>1. Word Document Types of Digital Watermark
  8. 8. <ul><li>Visible watermark </li></ul><ul><li>The implementation of visible watermarks can be applied in following areas </li></ul>2. On Images Types of Digital Watermark
  9. 9. <ul><li>Visible watermark </li></ul>2. Multimedia Files Types of Digital Watermark Click on image to Play
  10. 10. <ul><li>Invisible watermark </li></ul><ul><li>The watermark will not appear on the image and its existence can be determined using appropriate watermark extraction or detection algorithm. </li></ul><ul><li>Explanation </li></ul><ul><li>An invisible watermark technique consist of an encoding process and a decoding </li></ul><ul><li>process. </li></ul>Types of Digital Watermark
  11. 11. <ul><li>Invisible watermark </li></ul>Types of Digital Watermark How to implement ? Step -1 Select randomly the area of image to obtain its pixel values A=
  12. 12. <ul><li>Invisible watermark </li></ul>Types of Digital Watermark How to implement ? Step -2 Convert into its binary values B= A=
  13. 13. <ul><li>Invisible watermark </li></ul>Types of Digital Watermark How to implement ? Step -3 Form a watermarking key Watermark Key A= C= B=
  14. 14. <ul><li>Invisible watermark </li></ul>Types of Digital Watermark How to implement ? Step -4 The OR Operation is used B= D= B + C 01100101 00000011 01101000 01100100 00000001 01100101 01100110 00000010 01101000 01100111 00000000 01100111
  15. 15. <ul><li>Summery </li></ul><ul><li>1. Select randomly area of image and get its pixel values </li></ul><ul><li>2. Obtain its digital values </li></ul><ul><li>3. Convert to binary </li></ul><ul><li>4. Get a key matrix consisting binary values </li></ul><ul><li>5. Embed watermark using D:= B OR C </li></ul>Types of Digital Watermark A= B= C=
  16. 16. Types of Digital Watermark 01100101 00000011 01101000 Encoder Key Data ENCODING Algorithm Note Watermark will not effect the composition of image
  17. 17. <ul><li>We have add a invisible water mark in the image </li></ul><ul><li>The process of embedding the invisible watermark in image </li></ul><ul><li>is called ENCODING </li></ul>Achievement
  18. 18. <ul><li>Invisible watermark </li></ul><ul><li>We have embed the watermark in image </li></ul><ul><li>Can this image be owned by others? </li></ul>Types of Digital Watermark The Answer is yes What is the function of watermark ?
  19. 19. <ul><li>Example </li></ul><ul><li>1. Mr. Ali Compose a image </li></ul><ul><li>2. He then embed a watermark in it </li></ul><ul><li>3. Later on Mr.Jamil access this image and modify it and clam its ownership </li></ul><ul><li>4. Mr.Ali can detect his image by extracting the embedded watermark and can reclaim the </li></ul><ul><li>ownership </li></ul>
  20. 20. <ul><li>Invisible watermark Decoding </li></ul><ul><li>The process of extracting the embedded watermark from image is called Decoding. </li></ul><ul><li>The image can only be decoded by using the decoded algrothem with the key which was used for encoding. </li></ul>Types of Digital Watermark 01101000 Extract the encoded data from image Input to Decoding Algorithm Detect watermark Algorithm 01100101
  21. 21. Example Extract Watermark Algorithm Watermark detected by the Algorithm and hence intellectual property can be saved.
  22. 22. Encoding & Decoding 01100101 00000011 01101000 Encoder Key Data ENCODING Algorithm Extract Watermark Algorithm DECODING Algorithm Communication Media 01101000
  23. 23. Mathematically Encoding X’ = EK (X,W) Hence X = Original Image W= watermark information being embedded K= user insertion key E= watermark insertion function X’ = Watermarked Image Mathematically Decoding W = DK’ (X’) Hence X’ = Watermarked image K’= extraction key D= watermark extraction function W= Extracted watermarked information
  24. 24. <ul><li>We have understand the process of extracting the </li></ul><ul><li>watermarked key from image </li></ul><ul><li>Encoding and Decoding Mathematically </li></ul>Achievement
  25. 25. Application of watermark <ul><li>1. Ownership Declaration </li></ul>
  26. 26. Application of watermark Finger Print IS File save ?
  27. 27. Application of watermark Finger Print Data Center-01 Data Center-02 Data Center-03 Network
  28. 28. Application of watermark Finger Print A invalid copy is found at any location Extract the embedded figure print From file A figure print is unique value form each data center Can identify the data center
  29. 29. Application of watermark Embed the number of copies to be allowed for copying embed in the hardware 4 4 3 2 1 Copy not allowed Click on image to Play
  30. 30. Application of watermark Fraud Detection Data Center-01 Data Center-02 Data Center-03 Network
  31. 31. <ul><li>5. ID Card & Security </li></ul>Application of watermark Muhammad Ishfaque Karim Ahmad Observe ID card WHAT IS THE PROBLEM ?
  32. 32. <ul><li>5. ID Card & Security </li></ul>Application of watermark Muhammad Ishfaque Muhammad Ishfaque Extract name using watermarked algorithm Muhammad Ishfaque Compare the to validate ID CARD. M Jamil M.jamil M.jamil Muhammad Ishfaque
  33. 33. <ul><li>We have understand the application of water </li></ul><ul><li>mark </li></ul>Achievement
  34. 34. <ul><li>Robustness </li></ul><ul><li>The ability of watermark to provide the resistance against the modification of image is </li></ul><ul><li>called robustness </li></ul><ul><li>Modification </li></ul>Original Image Properties of Watermark Resize Rotation & Compression
  35. 35. <ul><li>No perceptibility </li></ul><ul><li>“ When we embed a invisible watermark by changing it bits it will not effect Human visual </li></ul><ul><li>system” </li></ul><ul><li>Modification </li></ul>Original Image Properties of Watermark Watermarked image
  36. 36. <ul><li>Non Detectable </li></ul><ul><li>Design a watermark that is not detectable by the outer attacks </li></ul><ul><li>Complexicity </li></ul><ul><li>The amount of time required to encode & decode a image is called complexicity </li></ul>Properties of Watermark
  37. 37. <ul><li>We have understand the properties of watermarks </li></ul>Achievement
  38. 38. Methods of Water Marking <ul><li>Water Marking in Spatial domain </li></ul><ul><li>The values of the image pixels are directly modified based on the </li></ul><ul><li>water mark that has to be embedded. </li></ul><ul><li>Advantage </li></ul><ul><li>Simple </li></ul><ul><li>Less computational required </li></ul><ul><li>Drawback </li></ul><ul><li>No security against modification </li></ul>
  39. 39. Methods of Water Marking <ul><ul><li>Water marking in frequency domain </li></ul></ul><ul><ul><li>A distributed sequence inserted into the perceptually most significant </li></ul></ul><ul><ul><li>frequency components. </li></ul></ul>Image: 11001010 00110101 00011010 00000000... Watermark: 01 01 10 11... Watermarked Image: 110010 11 001100 10 00011 100 000000 11 ...
  40. 40. <ul><li>Thanks </li></ul>

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