Abstract

Small sample size is one of the most challenging problems in face recognition due to the difficulty of sample collection in many real-world applications. By representing the query sample as a linear combination of training samples from all classes, the so-called collab- orative representation based classification (CRC) shows very effective face recognition performance with low computational cost. However, the recognition rate of CRC will drop dramatically when the available train- ing samples per sub ject are very limited. One intuitive solution to this problem is operating CRC on patches and combining the recognition outputs of all patches. Nonetheless, the setting of patch size is a non- trivial task. Considering the fact that patches on different scales can have complementary information for classification, we propose a multi- scale patch based CRC method, while the ensemble of multi-scale outputs is achieved by regularized margin distribution optimization. Our exten- sive experiments validated that the proposed method outperforms many state-of-the-art patch based face recognition algorithms.