In plain words: A simple penalty keeps different parts of a network's learned code uncorrelated, so it separates handwriting style or face identity from the label. Unlike classifiers that discard these details, it can redraw digits and faces with a new style or identity, inventing variation never labeled.
Abstract
Deep learning has enjoyed a great deal of success because of its ability to learn useful features for tasks such as classification. But there has been less exploration in learning the factors of variation apart from the classification signal. By augmenting autoencoders with simple regularization terms during training, we demonstrate that standard deep architectures can discover and explicitly represent factors of variation beyond those relevant for categorization. We introduce a cross-covariance penalty (XCov) as a method to disentangle factors like handwriting style for digits and subject identity in faces. We demonstrate this on the MNIST handwritten digit database, the Toronto Faces Database (TFD) and the Multi-PIE dataset by generating manipulated instances of the data. Furthermore, we demonstrate these deep networks can extrapolate `hidden' variation in the supervised signal.
Brian Cheung, Jesse A. Livezey, Arjun K. Bansal, Bruno A. Olshausen
arXiv:1412.6583 · cs.LG, cs.CV, cs.NE · submitted Dec 20, 2014 · updated Jun 17, 2015
abstract · pdf · html · Presented at International Conference on Learning Representations 2015 Workshop