Figure 2 .
Illustration of image patch extraction and the three levels of bag-of-words partitioning with weighting factors for the spatial pyramid approach. After feature description using the overlapping circular patches, three levels of bag-of-words partitioning are shown. The top level of partitioning is just a global bag-of-words representation.
Yuan et al. BMC Bioinformatics 2012 13:107 doi:10.1186/1471-2105-13-107