title: Shared Kernel Information Embedding for discriminative inference.
abstract: Latent variable models, such as the GPLVM and related methods, help mitigate overfitting when learning from small or moderately sized training sets. Nevertheless, existing methods suffer from several problems: 1) complexity, 2) the lack of explicit mappings to and from the latent space, 3) an inability to cope with multimodality, and 4) the lack of a well-defined density over the latent space. We propose an LVM called the Kernel Information Embedding (KIE) that defines a coherent joint density over the input and a learned latent space. Learning is quadratic, and it works well on small data sets. We also introduce a generalization, the shared KIE (sKIE), that allows us to model multiple input spaces (e.g., image features and poses) using a single, shared latent representation. KIE and sKIE permit missing data during inference and partially labeled data during learning. We show that with data sets too large to learn a coherent global model, one can use the sKIE to learn local online models. We use sKIE for human pose inference.
authors.affiliation: Department of Computer Science, University of Frankfurt, Robert-Mayer-Str. 10, 60325 Frankfurt, Germany. ro@cs.uni-frankfurt.de
authors.forename: Roland
authors.initials: R
authors.lastname: Memisevic
authors.forename: Leonid
authors.initials: L
authors.lastname: Sigal
authors.forename: David J
authors.initials: DJ
authors.lastname: Fleet
mesh_terms: D006801:Humans; D008962:Models, Theoretical; D010363:Pattern Recognition, Automated / Q000379:methods