BAG TECHNIQUE Bag technique-a tool making use of public health bag through wh...
Developing a classification framework for landcover landuse change analysis in Chile
1. Developing a classification framework for landcover
landuse change analysis in Chile
Dipl. Geoecologist Andreas Ch. Braun – Karlsruhe Institute of Technology – KIT
Institute of Photogrammetry and Remote Sensing - IPF
KIT – University of the State of Baden-Wuerttemberg and
National Research Center of the Helmholtz Association www.kit.edu
2. My background
Andreas Ch. Braun – Diploma Geoecologist
Works at the Institute of Photogrammetry and Remote Sensing
Kernel-based (Vegetation) Classification
Support Vector Machines
Import Vector Machines
Relevance Vector Machines
Feature Extraction Methods & Data Mining
Received a special Ph. D. scholarship in 2010 from the german
„Initiative for Excellence“
For a case study on Deforestation and Forest Degradation in Chile
2 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
3. The project on Deforestation in Chile
Analyse impact of substitution of native forests with plantations (Pinus,
Eucalyptus, Populus)
Landscape fragmentation
Habitat loss
Biodiversity loss
Approach:
Biodiversity data (point data) in the field, interpolate via remote
sensing/geoinformation on entire area (areal data)
3 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
4. How can we get from here....
Overall Accuracy 61,3%
4 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
5. .... to here?
Overall Accuracy 80,8% (+19,5)
5 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
6. Review: Image Morphology
Im. Matrix B Structuring Element S Im.Matrix B
Erosion: B⊖S :={z | Sz ⊆ B} → All Pixels in S must be in foreground
Dilatation: B⊕S :={z | Sz ∩ B ≠ ∅} → Min. 1 Pixel in S must be in foreground
Opening: Erosion dann Dilatation
Closing: Dilatation dann Erosion
Original Erosion Dilatation Opening Closing
6 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
7. How can mathematical morphology help?
Pinus radiata plantation
Populus nigra plantation
Nothofagus spec.
forest
7 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
8. How can mathematical morphology help?
Toy-Example: Classification of plantations, forests, open soils
8 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
9. How can mathematical morphology help?
Toy-Example: Classification of plantations, forests, open soils
9 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
10. How can mathematical morphology help?
Toy-Example: Classification of plantations, forests, open soils
Original Opening Closing
10 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
11. How can mathematical morphology help?
By using math. morphology, pixels are getting „more intelligent“. They
„know“ something about their neighbour pixels.
Math. Morphology is one possibility of integrating the spatial context into a
spectral classification.
„Mathematical morphology is a theory aiming to analyse the spatial
relationships between pixels“ (Fauvel et al., 2008, p.3805)
11 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
12. Morphological Attribute Profiles
M. Dalla Mura, J. A. Benediktsson, B. Waske, L. Bruzzone (2010): „Morphological
Attribute Profiles for the Analysis of Very High Resolution Images“. - IEEE
Transactions on Geoscience and Remote Sensing, Vol. 48(10).
Enhancements to the research on morphology in image classification by
J.A.Benediktsson.
Multilevel image analysis through opening, closing following these criteria:
Area
Moment of inertia
Std. Deviation
Diag. Of Bounding Box
Not only one filter size but a vast range of different structuring elements.
Graph-based approach increases computational performance.
12 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
13. Graph-based approach
Math. Morphology so far on binary images. How can grayscale images
be used?
Grayscale image is a stack of binary thresholds (e.g.. 8bit, [0,...,255])
Intensity IKA IKA > 80 IKA > 120 IKA > 200 IKA > 240
Within this stack, a 256 level graph of connected components exits.
13 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
14. Morphological profile
For these connected components (CC), certain criteria are checked
Area: Is the area of a CC < the area of the structuring element ?
Inertia: Is the extendedness of a CC < structuring element ?
Std. σ: ...
Diag. BB: ...
If criteria are met, one image opening and one image closing is
performed.
Not only one structuring element is used, but an entire range →
morphological profile.
14 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
15. Morphological profile
Afterwards, for classification we have:
One original image Im
Openings Opn, n=1,...,i, for different structuring elements
Closings Cln, n=1,...,i, for different structuring elements
The morphological profile (MP) (Pesaresi, Benediktsson, 2000) is then:
MP={Cln, ...Im,...Opn}
Cl3 Cl2 Cl1 Im Op1 Op2 Op3
Instead of using only one channel and one MP, we can compute this on many
channels, resulting in many Mps: extended morphological profile (EMP)
(Benediktsson et al., 2005, Fauvel et al., 2008)
EMP={MPk1, MPk2, … , MPkm}
15 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
16. Additional features for classification
For each channel of Landsat ETM+, we compute the features
Area: 2 per λ (Opening, Closing)
Inertia: 2 per λ
Std.: 2 per λ
Diag.BB: 2 per λ
For 8 different λ
8(features) * 8(channels) * 8(lambdas) = 512 new features for
classification
16 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
17. Classification of Landsat ETM+ image
3 Subsets
1: Forested area
2: Urban area
3: Agricultural area
17 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
18. Subset 1: Forested area
Overall Accuracy 61,3%
18 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
19. Subset 1: Forested area
Overall Accuracy 80,8% (+19,5)
19 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
20. Subset 2: Urban area
Overall Accuracy 75,5%
20 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
21. Subset 2: Urban area
Overall Accuracy 92,2% (+16,7)
21 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
22. Subset 3: Agricultural area
Overall Accuracy 62,2%
22 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
23. Subset 3: Agricultural area
Overall Accuracy 89,2% (+27,7)
23 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
24. Conclusions
Morphological Attribute Profiles are a very good, though implicit,
method of integrating spatial context into spectrally motivated
classification.
Especially recommendable for classification of textured classed.
Accuracy on three subsets in a image of Chile could be raised
significantly.
24 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
25. Challenges
High dimensional feature space (>>500 features) can not be processed
with standard methods (maximum likelihood).
Specialized methods needed: kernel based:
Support vector machines
Import vector machines
Relevance vector machines
Considerable programming effort.
Computational expense requires high-perfomance PC (8-core
processor with >120 GB Ram in our case)
25 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing
26. References
M. Dalla Mura, J. A. Benediktsson, B. Waske, L. Bruzzone (2010): „Morphological Attribute
Profiles for the Analysis of Very High Resolution Images“. - IEEE Transactions on Geoscience
and Remote Sensing, Vol. 48(10).
M. Fauvel, J.A. Benediktsson, J. Chanussot, J.R. Sveinsson (2008): „Spectral and Spatial
Classification of Hyperspectral Data Using SVMs and Morphological Profiles“. - IEEE
Transactions on Geoscience and Remote Sensing, Vol. 46(10).
J.A. Benediktsson, J.A. Palmason, J.R. Sveinsson (2005): „Classification of Hyperspectral Data
From Urban Areas Based on Extended Morphological Profiles“. - IEEE Transactions on
Geoscience and Remote Sensing, Vol. 46(10).
P. Soille, M. Pesaresi (2002): „Advances in mathematical morphology applied to geoscience and
remote sensing“. - IEEE Transactions on Geoscience and Remote Sensing, Vol. 40(9).
M. Pesaresi, J.A. Benediktsson (2000): „Image Segmentation based on the derivate of the
morphological profile“.- In: Mathematical Morphology and Its Application to Image and Signal
Processing, J. Goustsias, L. Vincent, D.S. Bloomberg, Eds. Norwell, MA: Kluwer, 2000.
26 22.07.11 Dipl. Geoecologist Andreas Ch. Braun Institute of Photogrammetry and Remote Sensing