Keyphrases
- sparse representation
- dictionary learning
- image classification
- riemannian manifolds
- sparse coding
- face recognition
- euclidean space
- pattern recognition
- text classification
- feature extraction
- random projections
- manifold learning
- decision trees
- image patches
- machine learning
- dimensionality reduction
- unsupervised learning
- image representation
- data sets
- feature selection
- high dimensional data
- signal processing
- nearest neighbor
- training set
- feature space
- vector space
- natural images
- support vector machine
- feature vectors