1. A method comprising: determining, by one or more processors of a machine, a color histogram of a query image; determining, by one or more processors of the machine, a first image attribute of the query image; calculating, by one or more processors of the machine, a confidence score of the first image attribute, the confidence score quantifying a degree to which the first image attribute is present in the query image; and comparing, by one or more processors of the machine, the first image attribute of the query image to a second image attribute of an item image that depicts an item, the comparing of the first and second image attributes being based on the confidence score of the first image attribute of the query image.