poisson image editing & terrain synthesis howard zhou jie sun...
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Poisson Image Editing& Terrain Synthesis
Howard Zhou Jie [email protected] [email protected]
2003 . 4.29
Table of Contents
1. Introduction / motivation2. Poisson Image Editing3. Terrain Synthesis (Texture based methods)
4. Future work5. Conclusion
Table of Contents
1. Introduction / motivation2. Poisson Image Editing3. Terrain Synthesis (Texture based methods)
4. Future work5. Conclusion
Introduction / motivation
Poisson Image Editing Seamless
Texture based terrain synthesis Current method based on fractals Very limited control Terrain style adjusted by parameter tuning What if the user draws a rough sketch and
supply a height map and says: “I want this to be like this”
Poisson Image Editing
Review
Our implmentation
Matlab Sparse matrix PDF solver Use conjugate gradient solver
supplied by Matlab Can be faster if …
Seamless insertion
Inserting objects with holes
Inserting transparent objects
Texture flattening
Result directly related to Edge detection result
Local illumination changes
alpha = 0.05beta = 0.2
alpha = 0.05beta = 0.4
Seamless tiling
Good when seam is not significant Often needs to increase the contrast of
the result but don’t an automatic way, maybe use
histogram of the original image
Seamless tiling
Good when the seam is not significant
Seamless tiling
Show some more
Seamless tiling
Seamless tiling
Seamless tiling
Contrast can be globally fixed
But how?
Seamless tiling
Seams not good
Cannot be fixed
Table of Contents
1. Introduction / motivation2. Poisson Image Editing3. Terrain Synthesis (Texture based methods)
4. Future work5. Conclusion
Previous approachTexture based terrain synthesis
Current method based on fractals Very limited control Terrain style adjusted by parameter
tuning What if the user draws a rough
sketch and supply a height map and says: “I want this to be like this”
Texture based terrain synthesis
1. Image analogy2. Texture synthesis on laplacian +
piecewise seamless tiling3. Graph cut / seamless tiling4. Separating the details
Data: height map
Display height map
Image analogy
:
::
:
A A' B B'
A. Hertzmann, C. Jacobs, N. Oliver, B. Curless, D. Salesin.SIGGRAPH 2001
Texture by number
Texture by number
How do we get (A) automatically
Blurring (filtering) Texture flattening using edge
detection result or contour
Image analogy + (texture flattening + blurring)
Laplacian Synthesis
Regard laplacian as a particular texture
Texture synthesisIntegrate
Results
Terrain
Terrain
Problems & possible solutions
Depend on the boundary conditionsUse the boundary attached to the
Laplacian
There is only one unique solution of this linear system
Lost the power of Poisson editingShould use a non-conservative
gradient field
Graph cut + seamless tiling
Laplacian removing boundary(since the boundary is known)
Image smoothing edge (1 D)
Using Poisson Solver
Terrain Analysis
The detail of the terrain differs at different altitude
Terrain = f ( altitude )Altitude = g ( style )
Example: Terrain map
Low Frequency - Altitude
High Frequency – as a function of Altitude
Proposed Algorithm
Use “Copy & Paste” methods to generate an altitude map
Add high frequency probabilistically as indexed by the altitude map
Graph cuts/Image Quilting to make it seamless
Table of Contents
1. Introduction (motivation)2. Re-illumination3. Changing viewpoint4. Future work5. Conclusion
Future Work
Other texture methods (Graph cut, stocastic?)
Stylized map generation from real map Real map from stylized map
Map vs. terrain
Conclusion
Implemented poisson image editingTried several texture based terrain
synthesis methodsLots to be done!
Questions ?