1. Wavelet Based Still Image and Video Compression
Dr.H.L.Cycon
FHTW Berlin
(supported by Deutsche Telekom AG)
Waveletprojekt H.L.Cycon

2. Waveletprojekt H.L.Cycon
Collaborators
Detlev Marpe, HHI Berlin
Mark Palkow, HHI Berlin
Alexander Haderer, Charite Berlin
Guido Heising, HHI Berlin
Alexander Petukhov, STU St.Petersburg(Ru)
Philipp Schellbach,HHI Berlin
Gabi Blättermann, HHI Berlin
Waveletprojekt H.L.Cycon

3. Waveletprojekt H.L.Cycon
Overview
Introduction
Still Image Compression
Real-time Video Coding
Very low Bit Video Coding
Real-time Demo
Waveletprojekt H.L.Cycon

4. Wavelet Coder and Decoder
Image
lossless
decorelation
lossy quatizer
lossless entropy
coder
compressed
bitstream
Rec.Image
Waveletprojekt H.L.Cycon

5. PACC pre-coding

7. Conditional coding

8. Waveletprojekt H.L.Cycon
Methods
3-level dyadic decomposition (biorthortogonal filter pairs)
uniform quantization with central widened deadzone
sophisticated entropy coder (PACC + arithmetic coder)
Waveletprojekt H.L.Cycon

9. RD Lena & Barbara 265x265 8 bit per pixel
JPEG base line (Lena) +
DWPT PACC (Barbara) + + +
Waveletprojekt H.L.Cycon

10. Waveletprojekt H.L.Cycon
(SPIHT)
Waveletprojekt H.L.Cycon

12. Waveletprojekt H.L.Cycon
Medical Applications
there are Tera bytes of medical image data (anually)
doctors worry about lossy compression
but eg. for X-ray images moderate compression only takes out noise
compression is denoising
Waveletprojekt H.L.Cycon

13. Medical Application
80:1 DXR
20:1 DXR
Error
Error

14. Waveletprojekt H.L.Cycon
Butterfly (0riginal 2917kB)
Waveletprojekt H.L.Cycon

15. Waveletprojekt H.L.Cycon
Butterfly 26kB (1:112)
Waveletprojekt H.L.Cycon

16. Waveletprojekt H.L.Cycon
Real-time Video
speed up:
DWT: using short filters 3/5, MMX features
Precoder: stream lining, no ZT, simpler templates
ArithCoder: using Qcoder (LUT)
Waveletprojekt H.L.Cycon

17. Waveletprojekt H.L.Cycon
Results
Real-time SW wavelet-based VCS for ISDN and IP transmission
(SerWin prototyped for Deutsche Telekom)
10-15fps CIF (352x288) on PII 266 (coding and decoding simultaneously)
better visual quality than other VCS (eg. Proshare)
Waveletprojekt H.L.Cycon

18. Very Low Bit Coder (proposed at ITU-T for H26L)
Wavelet coder using PACC OBMC and Image Warping Prediction
Waveletprojekt H.L.Cycon

19. Waveletprojekt H.L.Cycon
There are experiments with conventional block-based MC, but for reaching a high coding gain it is necessary to have a scheme free of blocking artifacts.
Using a non block based temporal predictor then the advantages of the wavelet coder can be used, due to the frame based wavelet transform.
Waveletprojekt H.L.Cycon

20. Waveletprojekt H.L.Cycon
Proposal:
Very Low Bit Rate Hybrid Video Coding scheme combining
new biorthogonal filterbanks
image warping prediction,
overlapped block motion compensation (OBMC)
effective wavelet error coding (DWT+Q+PACC).
Waveletprojekt H.L.Cycon

23. Waveletprojekt H.L.Cycon
Advantages
A dense motion vector field is achieved by using a bilinear geometric transform (warp) which smoothly varies over the image
In addition to translational motion this model can describe rotation, shear and change in scale.
This control grid interpolation leads to a motion field without motion discontinuities.
Result: blocking artifact free prediction
Waveletprojekt H.L.Cycon

24. Waveletprojekt H.L.Cycon
Optmizations
problems arise at motion boundaries due to objects performing different motions=> employ overlapped block motion compensation (OBMC) in affected blocks (adaptive)
more optimizations like adaptive switching between high quality and bilinear pixel interpolation filters,
& more...
Waveletprojekt H.L.Cycon

26. Waveletprojekt H.L.Cycon
Waveletprojekt H.L.Cycon

27. Foreman

28. Waveletprojekt H.L.Cycon
Waveletprojekt H.L.Cycon

29. Waveletprojekt H.L.Cycon
Waveletprojekt H.L.Cycon

30. Containership

31. Waveletprojekt H.L.Cycon
Waveletprojekt H.L.Cycon

32. Waveletprojekt H.L.Cycon
Outlook
Best bases search parametrized by complexity Image Quality vs Complexity (frame wise )
Waveletprojekt H.L.Cycon

33. Waveletprojekt H.L.Cycon
Conclusion
Still image PACC codec outperforms most of the known high performance codecs (eg. SPIHT,JPEG 2000)
PACC prototype of SW-real-time-wavelet codec is better than SW realizations of H263 (Proshare)
Warping-OBM-PACC very low bit coder outperforms H263++ (ITU-T TMN10 reference coder) by a gain in PSNR of dB
high potential for further optimizations (block wise intra coding, wavelet packets, finer grid, B frames, RD optimizations)
Waveletprojekt H.L.Cycon