1. A method comprising: receiving an image; defining a region of visual context in the image; partitioning the region of visual context into sectors; producing a sub-histogram for each sector, wherein the sub-histograms represent which of the sectors contain which of one or more local interest points in the region of visual context; concatenating the sub-histograms produced for each sector to generate a histogram describing a contextual distribution of the region of visual context; and storing the histogram describing the contextual distribution of the region of visual context.