Unsupervised classification (Tutorial)
From AWF-Wiki
Unsupervised K-Means classification
- Add the raster layer 188_pca_indices.tif into a QGIS project.
- Open the k-means classification algorithm provided by the Orfeo toolbox. It can be found in the processing toolbar under Toolbox --> Orfeo Toolbox --> Learning --> Unsupervised KMeans image classification (see figure A).
- Set the 188_pca_indices layer as Input image.
- Training set size: 100000
- Set the Number of classes to 20 and the Number of iterations to 1000.
- The Convergence threshold should be set at 0.0001.
- Leave all other configurations as they are and click Run. The resulting image has 20 classes, labeled from 0 to 19.
- Open the k-means classification algorithm provided by the Orfeo toolbox. It can be found in the processing toolbar under Toolbox --> Orfeo Toolbox --> Learning --> Unsupervised KMeans image classification (see figure A).