1. Tour Guide Image Compression Image Manipulation Image Analysis Image Acquisition Image Perception Image Display Image Generation D.I.P. Theme Park

2. Why D.I.P.? Reasons for compression –Image data need to be accessed at a different time or location –Limited storage space and transmission bandwidth Reasons for manipulation –Image data might experience nonideal acquisition, transmission or display (e.g., restoration, enhancement and interpolation) –Image data might contain sensitive content (e.g., fight against piracy, conterfeit and forgery) –To produce images with artistic effect (e.g., pointellism) Reasons for analysis –Image data need to be analyzed automatically in order to reduce the burden of human operators –To teach a computer to “see” in A.I. tasks

3. Shannon’s Picture on Communication (1948) source encoder channel source decoder sourcedestination Examples of source: Human speeches, photos, text messages, computer programs … Examples of channel: storage media, telephone lines, wireless transmission … super-channel channel encoder channel decoder The goal of communication is to move information from here to there and from now to then

4. Source Coding in Image Communication: Image Compression  Why do we need image compression? -Example: digital camera (4Mpixel) Raw data – 24bits, 5.3M pixels  16M bytes 256M memory card ($30-50)  16 pictures JPEG encoder raw image (16M bytes) compressed JPEG file (1M bytes) compression ratio=16  256 pictures

5. Lossless Image Compression  Definition - Decompressed image will be mathematically identical to the original one (zero error) - highly depends on the image type and content -Storage and transmission of medical images synthetic images >10 photographic images 1~3  Compression ratio  Applications

6. Popular Lossless Image Compression Techniques  WinZip - Based on the celebrated Lempel-Ziv algorithm invented nearly 30 years ago -Based on an enhanced version of LZ algorithm by Welch in 1983 -Was introduced by CompuServe in 1987 and made popular until it was not royalty-free in 1994  GIF (Graphic Interchange Format)  PNG (Portable Network Graphics) GIF Liberation Day: June 20, 2003

7. Lossy Image Compression JPEG decoder original raw image (262,144 bytes) compressed JPEG file (20,407 bytes) decompressed image high compression ratio low compression ratio low quality high quality Q Q 100 0

8. From JPEG to JPEG2000 JPEG (CR=64)JPEG2000 (CR=64) discrete cosine transform basedwavelet transform based

9. Tour Guide Image Compression Image Manipulation Image Analysis Image Acquisition Image Perception Image Display Image Generation D.I.P. Theme Park

10. salt and pepper (impulse) noise Image Manipulation (I): Noise Removal Noise contamination is often inevitable during the acquisition additive white Gaussian noise

11. License plate is barely legible due to motion blurring Image Manipulation (II): Deblurring

12. overly-exposed image Image Manipulation (III): Contrast Enhancement under-exposed image

13. Example: aliasing artifacts in MRI image acquisition Tradeoff between scanning time and image quality Ideal quality, slow scanning nonideal quality, fast scanning Image Manipulation (IV): Aliasing Reduction

14. small large digital zooming 1M pixels 4M pixels Resolution enhancement can be obtained by common image processing software such as Photoshop or Paint Shop Pro Image Manipulation (V): Image Interpolation

15. F.Y.I.: search “Gigapixel images” by Google http://triton.tpd.tno.nl/gigazoom/Delft2.htm = + Merge multiple images of the same scene into one with larger FOV Image Manipulation (VI): Image Mosaicing There exist several mosaicing software for automatic stitching

16. blocks contaminated by channel errors Image Manipulation (VII): Error Concealment

17. Block artifacts Image Manipulation (VIII): Deblocking/Deringing Ringing artifacts

18. jittering noise Image Manipulation (IX): Dejittering

19. Image Manipulation (X): Image Inpainting

20. Image Inpainting Application: Restore Old Photos

21. 25,680 colors (24 bits)256 colors (8 bits) Applications: video cell-phone, gameboy, portable DVD Image Manipulation (XI): Color Quantization

22. grayscale: 0-255halftoned: 0/255 Image Manipulation (XII): Image Halftoning

23. original scrambled Image Manipulation (XIII): Image Scrambling/Hashing

24. Original imageModified image Image Manipulation (XIV): Image Watermarking

25. Image Manipulation (XV): Image Stylization

26. Abyss computer generated Image Manipulation (XVI): Image Rendering

27. Image-based Rendering

28. Tour Guide Image Compression Image Manipulation Image Analysis Image Acquisition Image Perception Image Display Image Generation D.I.P. Theme Park

29. Image Analysis (I): Edge Detection

30. Image Analysis (II): Face Detection

31. Image Analysis (III): Change Detection

32. Change Detection in Medical Application

33. Image Analysis (IV): Image Matching Antemortem dental X-ray recordPostmortem dental X-ray record

34. Image Matching in Biometrics Two deceivingly similar fingerprints of two different people

35. Image Analysis (V): Image Segmentation

36. License number can be automatically extracted from the image of license plate Image Analysis (VI): Object Recognition

37. Object Recognition in Military Applications

38. Image-based monitoring system prevents drowning Image Analysis (VII): Event Recognition

39. Only send out “important” motion pictures such as home-runs Image Analysis (VIII): Video Summarization

40. retrieved building images Image Analysis (IX): Content-based Image Retrieval