Hierarchical image representation via multi-level sparse coding

This paper presents a hierarchical model for robust image representation. We first introduce multi-level sparse coding algorithm and normalized max pooling strategy which are designed to obtain meaningful sparse codes and robust pooled codes, respectively. With the sparse codes and pooled codes, a hierarchical architecture is built and more robust features are extracted at the second layer. The proposed method has been evaluated on two widely used datasets: Caltech-101 and Caltech-256, and experimental results demonstrate that the proposed method is both effective and robust in image representation compared with the state-of-the-art.