A shape feature based bovw method for image classification using N-gram and spatial pyramid coding scheme

Image classification is a general visual analysis task based on the image content coded by its representation. In this research, we proposed an image representation method that is based on the perceptual shape features and their spatial distributions. A natural language processing concept, N-gram, is adopted to generate a set of perceptual shape visual words for encoding image features. By combining hierarchical visual words and spatial pyramid, Spatio-Shape Pyramid representation is constructed to reduce the semantic gaps. Experimental results show that the proposed method outperforms other state-of-the-art methods.