1. Pattern-based Texture Metamorphosis Z. Liu, C. Liu, and H. Shum Microsoft Research Asia Y. Yu UIUC

2. Image Morphing vs. Texture Morphing Specify Features and Correspondence * Specify Features and Correspondence * Warp Generation Warp Generation Transition Control Transition Control Image Morphing * Require a lot of human intervention

3. Textures are usually homogenous with features everywhere. Textures are usually homogenous with features everywhere. Hard to specify features Hard to specify features Hard to build correspondence Hard to build correspondence Image Morphing vs. Texture Morphing Texture Morphing

4. Direct Blending Does Not Work Random Semi-structuredRegular source target

5. Interesting Problems In Texture Morphing What pair of textures? What pair of textures? Similar and repeatable patterns. Similar and repeatable patterns. Pattern distributions are alike. Pattern distributions are alike. What is the feature? What is the feature? User define pattern. User define pattern. How to extract so many patterns? How to extract so many patterns? Semi-automatic approach. Semi-automatic approach. How to build correspondence? How to build correspondence? Generate a smooth warp field. Generate a smooth warp field.

6. Our Approach 1. Pattern Detection and Alignment 1. Pattern Detection and Alignment 2. Establishing Correspondence 2. Establishing Correspondence 3. Warping and Blending 3. Warping and Blending Source textureTarget texture Morphing sequence

7. Pattern Representation Pattern Representation Shape Distance Shape Distance Local Feature Distance Local Feature Distance Pattern Representation & Distance Measurement

8. Pattern Detection & Alignment Step1: Initialization by Generalized Hough Transform (GHT). Step1: Initialization by Generalized Hough Transform (GHT). Step2: Alignment by top-down verification. Step2: Alignment by top-down verification. Step3: Refinement by human intervention. Step3: Refinement by human intervention.

9. Step1: Initialization Pattern Detection & Alignment User selected pattern Voting of a pixel Intensity imageLocal maximum Original texture

10. (a) Independently update each landmark (a) Independently update each landmark (b) Update shape (b) Update shape Iteratively do (a) and (b). Iteratively do (a) and (b). Pattern Detection & Alignment Step2: Alignment

11. Alignment Process GHT initializationalignment

12. Pattern Detection & Alignment Step3: Refinement (a) False detection (a) False detection (b) False alignment (b) False alignment (c) More than one types of pattern (c) More than one types of pattern

13. Correspondence by Minimizing Morphing Path

14. Warping and Blending From S.Lee

15. More Results source target Pattern selected

16. Discussion About Pattern Selection About Pattern Selection Can be any shape Can be any shape User is responsible User is responsible About Correspondence and Transition Control About Correspondence and Transition Control Problem of crowd patterns Problem of crowd patterns About Warp Generation About Warp Generation MFFD vs. as rigid as possible MFFD vs. as rigid as possible

17. Thank you !