1 / 33

Wavelet-Based Still Image and Video Compression Overview

Explore Dr. H.L. Cycon's wavelet compression project, including still image and real-time video coding, medical applications, and optimizations for enhanced compression performance. Discover advanced techniques, results, and future outlook for wavelet compression in imaging and video processing.

patriciassmith
Download Presentation

Wavelet-Based Still Image and Video Compression Overview

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. Wavelet Based Still Image and Video Compression Dr.H.L.Cycon FHTW Berlin http://www.fhtw-berlin.de/Projekte/Wavelet (supported by Deutsche Telekom AG) Waveletprojekt H.L.Cycon

  2. 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. 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 entropy coder lossless decorelation lossy quatizer compressed bitstream Rec.Image Waveletprojekt H.L.Cycon

  5. PACC pre-coding

  6. Conditional coding

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

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

  9. (SPIHT) Waveletprojekt H.L.Cycon

  10. 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

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

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

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

  14. 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

  15. 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

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

  17. There are experiments with conventional block-based MC, but for reaching a highcoding gain it is necessary to have a scheme free of blocking artifacts. • Using a nonblockbased temporal predictorthen the advantages of the wavelet coder can be used, due to the frame based wavelet transform. Waveletprojekt H.L.Cycon

  18. 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

  19. Advantages • A dense motionvector 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

  20. 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

  21. Waveletprojekt H.L.Cycon

  22. Foreman

  23. Waveletprojekt H.L.Cycon

  24. Waveletprojekt H.L.Cycon

  25. Containership

  26. Waveletprojekt H.L.Cycon

  27. Outlook Best bases search parametrized by complexityImage Quality vs Complexity (frame wise ) Waveletprojekt H.L.Cycon

  28. 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 0.5-1.5 dB • high potential for further optimizations (block wise intra coding, wavelet packets, finer grid, B frames, RD optimizations) Waveletprojekt H.L.Cycon

More Related