| Description |
Recent developments have shown that restricted Boltzmann machines (RBMs) are useful in learning the features of a given dataset in an unsupervised manner. In the case of digital images, RBMs consider the image pixels as a set of real-valued random variables, disregarding their spatial layout. However, as we know, each image pixel is correlated with its neighboring pixels, and direct modeling of this correlation might help in learning. Therefore, this thesis proposes using a Markov random field prior on the weights of the RBM model, which is designed to model these correlations between neighboring pixels. We compared the test classification error of our model with that of a traditional RBM with no prior on the weights and with RBMs with L1 and L2 regularization prior on the weights. We used the NIST dataset, which consists of images of handwritten digits for our experiments. |
