Systems and methods are provided for calculating and using histogram descriptors to compare images and to identify visually similar content. According to at least one embodiment, multiple histograms descriptors are calculated for individual images of a collection of content. These histogram descriptors may be used to identify two or more visually similar images in the collection of content. For example, if a user identifies an image of an item of interest, then embodiments search across the collection of content to identify other images of items that are visually similar to the selected item of interest. To do so, embodiments search across the histogram descriptors of the images in the collection of content to identify one or more images that have histograms descriptors that are similar to the histograms descriptors of the image of the selected item of interest.