1. A method comprising: dividing an image into a plurality of image regions; determining a plurality of gradients for each of a plurality of cells of an image region, wherein the image region is divided into the plurality of cells prior to determining the plurality of gradients; selecting a bin configuration, wherein selecting a bin configuration comprises selecting a bin configuration having a bin positioned at a location coinciding with the gradient having a greatest probability; assigning the gradients for a respective cell to a respective one of a plurality of bins of the bin configuration that has been selected; determining a plurality of feature descriptors, wherein each feature descriptor includes a representation of a distribution of gradients between the plurality of bins of a respective cell; and compressing the plurality of feature descriptors comprising the gradient distributions of the respective cells.