Abstract: A method includes deriving a plurality of semantic categories for representing important semantic cues in images, where each semantic category is modeled through a combination of perceptual features that define the semantics of that category and that discriminate that category from other categories; for each semantic category, forming a set of the perceptual features comprising required features and frequently occurring features; comparing an image to said semantic categories; and classifying said image as belonging to one of said semantic categories if all of the required features and at least one of the frequently occurring features for that semantic category are present in said image. A database contains image information, where the image information includes at least one of already classified images, network locations of already classified images and documents containing already classified images. The database is searched for images matching an input query, comprising, e.g., an image, text, or both.