1. The Trilateral Filter for High Contrast Images and Meshes
Prasun Choudhury and Jack Tumblin
Speaker: Di jiantao
Feb 28,2008

2. About the author---Prasun Choudhury
Current:
Computer Scientist at Adobe Systems Inc.
Past:
Computer Graphics Research Engineer at Nokia Research Center.
Staff software Engineer at Intel Corp.
Simulation Software Engineer at Immersion Corp.
Education:
Northwestern University
Indian Institute of Science
Jadavpur University
RKM Narendrapur

3. About the author---Jack Tumblin
Associate Professor, EECS Department, Computer Science, Northwestern University.
Research interests:
Computational Photography & Illumination.
Computer Vision and Interactive Computer Graphics.
High Dynamic Range (HDR) Images and Image Processing.
Digital Archives of Visual Appearance for Museum Collections.
Human Visual Perception, Psychophysics, and Physiology.

4. Filter methods: Gaussian Filter* =

5. Filter methods: Bilateral Filter* =

6. Gaussian, Bilateral and Trilateral Filter Windows
The changes of Trilateral filter:
Tilting.
S measures its closeness to the plane through I(x).
Adaptive neighborhood.

7. Step 1 of Trilateral Filter for Image
Bilateral smooth gradients

8. Step2 of Trilateral Filter for Image
Trilateral smooth image
Compute approximate value
Compute
Filter

9. Results

10. Results

11. Results

12. Application 1: Contrast Reduction
Contrast reduction method based on edge-preserving filters.
Base is compressible and Details are incompressible.
Compress:

13. Results of Contrast Reduction

14. Results of Contrast Reduction

15. Results of Contrast Reduction

16. Application 2: Mesh Smoothing
A two-step process:
Trilateral normal filtering.
Bilateral smooth vertex normal.
Trilateral vertex filtering.

17. Signs Definition ---vertex position ---vertex normal ---mesh face
---face normal
---face center point
---bilaterally smoothed vertex normal
---tangent plane pass through

18. Trilateral normal filter

19. Trilateral Vertex Filter
is the projection of on the plane

20. Results of Mesh Smoothing
Original Model
Smoothed Model
Noisy Model

21. Results of Mesh Smoothing

22. Results of Mesh Smoothing

23. Thank you!