Keyphrases
- nonnegative matrix factorization
- image retrieval
- probabilistic latent semantic indexing
- matrix factorization
- negative matrix factorization
- active set
- data representation
- nonnegative matrix
- least squares
- principal component analysis
- relevance feedback
- spectral clustering
- image representation
- document clustering
- sparsity constraints
- original data
- data sets
- digital libraries
- objective function
- machine learning