Automatic classification for field crop insects via multiple-task sparse representation and multiple-kernel learning

Classification of insect species of field crops such as corn, soybeans, wheat, and canola is more difficult than the generic object classification because of high appearance similarity among insect species. To improve the classification accuracy, we develop an insect recognition system using advanced multiple-task sparse representation and multiple-kernel learning (MKL) techniques. As different features of insect images contribute differently to the classification of insect species, the multiple-task sparse representation technique can combine multiple features of insect species to enhance the recognition performance. Instead of using hand-crafted descriptors, our idea of sparse-coding histograms is adopted to represent insect images so that raw features (e.g., color, shape, and texture) can be well quantified. Furthermore, the MKL method is proposed to fuse multiple features effectively. The proposed learning model can be optimized efficiently by jointly optimizing the kernel weights. Experimental results on 24 common pest species of field crops show that our proposed method performs well on the classification of insect species, and outperforms the state-of-the-art methods of the generic insect categorization.