1. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. 1 2012/08/14 指導教授：詹寶珠教授 報告者：陳正 旻 期末 DEMO line segment 的 GPU 實現

2. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. 2 Outline 演算法流程介紹 ( 附實作結果 ) 時間比較和加速倍數 實作影片 總結

3. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Flow chart 3

4. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Algorithm Line segment construction Two rules Color difference : Spatial distance : 4

5. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. (TIME)Line segment construction 5

6. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Flow chart 6

7. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Algorithm Initial Disparity Computation Matching cost : C AD : C CENSUS : Hamming distance of the two strings that stand for p and pd 7 String R. Zabih and J. Woodfill, “Non-parametric local transforms for computing visual correspondence,” in Proc. ECCV, 1994, pp. 151–158. d=1 LeftRight 2

8. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. (TIME)Initial Disparity Computation & Matching cost 8

9. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Algorithm Cost aggregation Winner-take-all 9 d=1 LeftRight

10. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. (TIME)Cost aggregation & Winner-take-all 10

11. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. 初步結果 左圖的 Depth 右圖的 Depth 11

12. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Flow chart 12

13. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Algorithm Seed Pixel Detection Two rules 13

14. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. (TIME)Seed Pixel Detection 14

15. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Flow chart 15

16. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Algorithm Scanline Propagation Aa, if p is in occluded regions. d Ss, if p is near depth discontinuities. a is replaced by the linearly interpolated results of and in all other conditions. 16

17. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. (TIME)Scanline Propagation 17

18. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Scanline Propagation 之後的結果 18

19. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Flow chart 19

20. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Algorithm Disparity Refinement Vertical voting : We collect disparity votes in a vertical line segment that starts at pixel and ends at pixel,if the color difference is smaller than the threshold value, the votes on disparity increase by 1. c 20

21. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. (TIME)Vertical voting 21

22. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Vertical voting 之後的結果 22

23. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. 再加入 BilateralFilter 之後的最終結果 23

24. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. GPU 運算時間 CPU 運算時間 24

25. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. 時間比較和加速倍數 Line Segment 漢明距離單點 cost 總 cost CPU0.114000 (S)0.4819990.9739990.352999 GPU0.002498 (S)0.0048680.0918730.016956 加速約 45 ( 倍 ) 約 99 ( 倍 ) 約 11 ( 倍 ) 約 21 ( 倍 ) 25 Seed pixel Scan Line Vertical voting DBF GPU 總時間 0.0200000.0170000.0980002.059997 0.0000330.0002390.0023140.0020.120781 約 606 ( 倍 ) 約 71 ( 倍 ) 約 42 ( 倍 ) 約 18 ( 倍 )

26. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. 實作影片 26

27. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. 總結 GPU 加速持續改進。 再加入各種不同方法使結果更好。 27

28. Electrical Engineering Department of National Cheng Kung University Smart Media & Intelligent Living Excellence Lab. Thank for your attention! 28