Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Image Approximation with Transparent Introduction Triangles - - PowerPoint PPT Presentation
Image Approximation with Transparent Introduction Triangles - - PowerPoint PPT Presentation
Image Approximation with Transparent Triangles Kevin Stock Image Approximation with Transparent Introduction Triangles Objective Function Search Techniques Kevin Stock Examples Future Work Source Images December 10, 2010 Example
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Example (using 1000 triangles)
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Inspiration
Roger Alsing’s Genetic Programming: Evolution of Mona Lisa Not actually genetic programming.
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Model
The image is drawn from an array of triangles, rendered by OpenGL in order. Each triangle is composed of 10 scalars: r, g, b, a, x1, x2, x3, y1, y2, y3. All 10 scalars are constrained to the range [0, 1].
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Objective Function
RGB TSS Easy to implement. Good enough results. HSV TSS Much slower than comparing RGB. Optionally weight channels: V is considered more important than H or S in encoding. Surprisingly, worse results than using RGB.
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
RGB TSS
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
HSV TSS
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
HSV TSS (Weighted)
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Hill Climber
Algorithm At each iteration, change one value of one triangle to a new value. If the new version is better keep it. Performance Very slow convergence.
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Simulated Annealing
Algorithm Start with big changes, over time make smaller changes. Never accepts a worse solution. Performance Converges faster than hill climber. To help avoid local minimums, the system is ’reheated’
- ccasionally allowing big changes again.
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Incremental Start
Algorithm Start with one triangle, add another triangle every n iterations. Similar to hill climber, but half of all iterations attempt to mutate the most recently added triangle. Performance Not actually a complete algorithm. Can be used to seed other algorithms, excellent results with SA.
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Genetic Algorithm
Algorithm Uniform random selection of parents. One point crossover reproduction. Random mutations within fix range from starting values. Performance Not as good convergence as SA, but better than hill climber. Mutation step could probably be improved.
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
SA vs SA w/ Inc. Start (100 Tri’s, 90k Iter’s)
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
GA vs SA (100 Tri’s, 600k Iter’s)
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
GA vs SA (50/200 Tri’s, 100k/650k Iter’s)
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
SA w/ Inc. Start (Iter. 1000)
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 5000
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 10k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 15k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 20k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 25k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 30k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 35k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 40k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 45k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 50k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 150k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 200k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 380k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 460k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 580k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
- Iter. 650k
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
SA w/ Inc. Start (500 Tri’s, 780k Iter’s)
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
SA w/ Inc. Start (500 Tri’s, 1800k Iter’s)
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
GA (500 Tri’s, 600k Iter’s)
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Future Work
Alternative objective functions Minimum size or angle constraint on triangles Eliminate non-contributing triangles Non-uniform choice of channel to mutate Combination of GA/SA for global/local search More search techniques
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Mona Lisa
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Eva Green
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images
Tart
Image Approximation with Transparent Triangles Kevin Stock Introduction Objective Function Search Techniques Examples Future Work Source Images