1. M16758 – Influence of views and depth compression onto quality of synthesized views July, 2009, London Krzysztof Wegner Krzysztof Klimaszewski Marek Domański team supervisor: Marek Domański Chair of Multimedia Telecommunications and Microelectronics Poznań University of Technology, Poland

2. M16758 – Influence of views2 Multiview system

3. M16758 – Influence of views3 Multiview system

4. M16758 – Influence of views4 Depth map compression issues How to compress depth maps? Can MVC be used? How to share bandwidth between views and depth maps? Which one is more important? What is the optimal ratio?

5. M16758 – Influence of views5 Depth map features Differences between depth maps and views Depth MapsViews only one color component three color components limited textureabundance of texture prominent contours less prominent contours accurate depth value important accurate value not necessary

6. M16758 – Influence of views6 Depth map decimation What is the influence of depth map decimation on the view synthesis process?

7. M16758 – Influence of views7 Test setup

8. M16758 – Influence of views8 View quality measurement

9. M16758 – Influence of views9 Cameras and software The following software and camera numbers were used: Data set Original pair (A and C) Synthesized view (B) Book Arrival7 and 108 Pantomime38 and 4139 Newspaper3 and 64 VSRS version 3 DERS version 3 JMVC version 3

10. M16758 – Influence of views10 Results Synthesis quality for UNCOMPRESSED view and depth map Data set PSNR using uncompressed data [dB] PSNR using uncompressed data (depth maps decimated with factor 2) [dB] Book Arrival36.178736.1865 Pantomime35.590835.6526 Newspaper29.219129.3317

11. M16758 – Influence of views11 Results Results for compressed data – Book Arrival

12. M16758 – Influence of views12 Results Results for compressed data – Book Arrival

13. M16758 – Influence of views13 Results Results for compressed data – Pantomime

14. M16758 – Influence of views14 Results Results for compressed data – Pantomime

15. M16758 – Influence of views15 Results Results for compressed data – Newspaper

16. M16758 – Influence of views16 Results Results for compressed data – Newspaper

17. Subjective tests A single-stimulus test was conducted 15 spectators quality was rated from 5 (“imperceptible artifacts”) to 0 (“very bad with annoying artifacts”) The original video from actual real camera was used as hidden reference. M16758 – Influence of views17

18. Subjective quality 1/3 M16758 – Influence of views18

19. Subjective quality 2/3 M16758 – Influence of views19

20. Subjective quality 3/3 M16758 – Influence of views20

21. Optimal QD for depth map Depth quantization parameter index QD has negligible (less than 0.2 dB decrease) impact on synthesized view quality as long its value is smaller than the following threshold estimated from the experiments M16758 – Influence of views21

22. M16758 – Influence of views22 Conclusions 1/2 it is possible to transmit the depth maps using MVC codec with sufficient quality view quality is much more important than depth quality in terms of synthesized view quality depth bitrate can be kept as low as 10 - 20 % of total bitrate without significant loss of synthesized view quality (for decimated depth map)

23. M16758 – Influence of views23 Conclusions 2/2 for a certain range of values of quantization parameter index for depth compression (QD), no change of synthesized view quality is noticeable higher compression rate with comparable quality can be obtained by decimating the depth map by a factor of 2

24. M16758 – Influence of views24 Recommendations We recommend to consider usage of decimated depth map in future depth map coding experiments.