Multi-layer PCA Network for Image Classification

Mubarakah Alotaibi, Richard C. Wilson

Abstract: PCANet is a simple deep learning baseline for image classification, which learns the filters banks by PCA instead of stochastic gradient descent (SGD) in each layer. It shows a good performance for image classification tasks with only a few parameters and no backpropagation procedure. However, PCANet suffers from two main problems. The first problem is the features explosion which limits its depth to two layers. The second issue is the binarization process which leads to discriminative information loss. To handle these problems, we adopted CNN-like convolution layers to learn the PCA filter-bank and reduce the number of dimensions. We also used second-order pooling with z-score normalization to replace the histogram descriptor. The late fusion method is used to combine the class posteriors generated each layer. The proposed network has been tested on image classification tasks including MNIST, Cifar10, Cifar100 and Tiny ImageNet databases. The experimental results show that our model achieves better performance than standard PCANet and is competitive with some CNN methods.