PT Journal AU Thanh Ha Do Salvatore Tabbone Oriol Ramos Terrades TI Sparse representation over learned dictionary for symbol recognition SO Signal Processing JI SP PY 2016 BP 36 EP 47 VL 125 DE Symbol Recognition; Sparse Representation; Learned Dictionary; Shape Context; Interest Points AB In this paper we propose an original sparse vector model for symbol retrieval task. More speci cally, we apply the K-SVD algorithm for learning a visual dictionary based on symbol descriptors locally computed around interest points. Results on benchmark datasets show that the obtained sparse representation is competitive related to state-of-the-art methods. Moreover, our sparse representation is invariant to rotation and scale transforms and also robust to degraded images and distorted symbols. Thereby, the learned visual dictionary is able to represent instances of unseen classes of symbols. ER