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P. Arbelaez, M. Maire, C. Fowlkes, J. Malik. Contour Detection and Hierarchical image Segmentation. IEEE Trans. on PAMI , 2011.
CONTOUR DETECTION AND HIERARCHICAL IMAGE SEGMENTATION
Student: Hsin-Min ChengAdvisor: Sheng-Jyh Wang
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Outline
Introduction Contour Detection Hierarchical Segmentation Results Conclusion
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Introduction
Original Image Contour
Contour
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Introduction
Original Image Segmentation
Segmentation
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Introduction From Contour to Segmentation
Original Image SegmentationContour
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Introduction Goal
Contour Detection Hierarchical Segmentation from Contours
Original Image SegmentationContour
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Outline
Introduction Contour Detection Hierarchical Segmentation Results Conclusion
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Contour Detection
1. Learn local boundary cues 2. Global framework to capture
closure, continuity3. Local Cues and global cues
combination
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Learn local boundary cues
Image Local Boundary Cues
Model
BrightnessColorTexture
Cue Combination
Contour Detection
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Learn local boundary cues Brightness L*a*b* colorspace
Color L*a*b* colorspace
Texture Convolve with 17 filters
Filters for creating textons
Contour Detection
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Learn local boundary cues Oriented gradient of histograms Example
Gradient magnitude G at location(x, y)
Three scales of r
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Contour Detection
ure ]2 , ,2
[
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Learn local boundary cues Local Cues Combination
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Contour Detection
ure ]2 , ,2
[ r
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Global framework to capture closure, continuityContour Detection
V: image pixels
E: connections between pairs of nearby pixels
=>Build a weighted graph G=(V,E) from image
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Global framework to capture closure, continuityContour Detection
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Local Cues and global cues combinationContour Detection
Local Cues Global cues
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Outline
Introduction Contour Detection Hierarchical Segmentation Results Conclusion
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Hierarchical Segmentation Multiple Segmentations
Fixed resolution
Hierarchy of Segmentations Flexible resolution adjustment
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Hierarchical Segmentation1. From contours to segmentation2. Hierarchical segmentation by
iterative merging
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Hierarchical Segmentation From contours to segmentation
Watershed Transform Concept
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Hierarchical Segmentation From contours to segmentation
Watershed Transform Example
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Hierarchical Segmentation From contours to segmentation
Watershed Transform
Boundary strength ArtifactsWeight each arc
Hierarchical Segmentation From contours to segmentation
Oriented Watershed Transform
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WTOWT
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Hierarchical Segmentation Hierarchical segmentation by iterative
merging Hierarchical segmentation
Example
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Brief SummaryOriginal Image
- Local cues - Global cues
Oriented Gradientof histograms
Contour
Oriented Watershed Transform
Iterative Merging
Hierarchical Segmentation
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Outline
Introduction Contour Detection Hierarchical Segmentation Results Conclusion
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Result
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Result
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Result
Evaluation of segmentation algorithmsEvaluation of contour detector
BSDS300 Dataset
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Outline
Introduction Contour Detection Hierarchical Segmentation Results Conclusion
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Conclusion A high performance contour detector, combining
local and global image information
A method to transform any contour detector signal into a hierarchy of regions while preserving contour quality
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Reference P. Arbelaez, M. Maire, C. Fowlkes and J. Malik. Contour Detection
and Hierarchical Image Segmentation. IEEE TPAMI, Vol. 33, No. 5, pp. 898-916, May 2011
P. Arbelaez, M. Maire, C. Fowlkes and J. Malik. From Contours to Regions: An Empirical Evaluation. In CVPR 2009.
P. Arbelaez and L. Cohen. Constrained Image Segmentation from Hierarchical Boundaries. In CVPR 2008.
