1 / 13

Wyner-Ziv Coding of Light Fields for Random Access

Wyner-Ziv Coding of Light Fields for Random Access. Overview. Light fields Predictive coding and random access Wyner-Ziv coding for light fields Simulation results . What is a Light Field?.

wilma
Télécharger la présentation

Wyner-Ziv Coding of Light Fields for Random Access

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. Wyner-Ziv Coding of Light Fields for Random Access

  2. Overview • Light fields • Predictive coding and random access • Wyner-Ziv coding for light fields • Simulation results

  3. What is a Light Field? A 4-D data set for image-based rendering,typically parameterized as a 2-D set of images. [Levoy and Hanrahan, 1996] [Gortler et al., 1996]

  4. decoded images level 0 level 1 level 2 desired image geometry model image 2 image 1 Light Field Coding using Prediction hierarchical prediction [Magnor and Girod, 2000] [Ramanathan et al., 2002][Chang et al., 2003]

  5. Rendering a Single Novel View Garfield light field How do we perform better than intracoding?

  6. Encoder Decoder Statistically dependent Wyner-Ziv Coding [Wyner and Ziv, 1976] Lossy compression with decoder side information

  7. Wyner-Ziv image Key image Wyner-Ziv Coding of Light Fields At the decoder, side information for decoding Wyner-Ziv image is rendered from available key images • Better rate-distortion performance than intracoding [Zhu, Aaron, Girod, 2003] • Similar work by [Jagmohan, Sehgal, Ahuja, 2003]

  8. bit-plane 2 bit-plane 1 Wyner-Ziv DCT Light Field Codec WZ image Decoded WZ image W Shape processing IDCT DCT Xk Xk’ qk qk’ Turbo Encoder Reconstruction level Quantizer Extract bit-planes Turbo Decoder … bit-plane Mk Side information Yk For each transform band k DCT Shape processing Rendering Key image Shape-adaptive decoding Shape-adaptive Intracoding K K’

  9. R-D Performance for WZ images Garfield light field 288 images each at 144x192 pixels Hemispherical camera setting with 8 rows and 32 columns Half of the images are WZ images

  10. 25% 2 dB Rendering a Single Novel View Garfield light field data set R-D Performance averaged over 20 novel views. Each novel view is rendered from closest 4 images.

  11. Sample Rendered View Intracoding 1.5 bpop, 33.8 dB Original Wyner-Ziv coding 1.4 bpop, 36.2 dB

  12. Summary • Wyner-Ziv coding of light field images for random access and compression efficiency • Up to 2 dB PSNR improvement over intracoding for rendering novel views • Single representation of data set multiple representation solution [Ramanathan and Girod, MMSP 2004]

  13. Sample Rendered View Intracoding 1.6 bpop, 33.7 dB Original Wyner-Ziv coding 1.9 bpop, 36.6 dB

More Related