16. A method performed by a computer system executing machine-readable instructions, the method comprising acts of: crawling webpages that include images using an automated indexer; detecting and tagging unwanted images based on features related to images, before an image download process; building a website model as a feature source; computing probability a file extension type is related to an unwanted image; and removing the unwanted images from an indexer download list before the image download process.
16. A method performed by a computer system executing machine-readable instructions, the method comprising acts of: crawling webpages that include images using an automated indexer; detecting and tagging unwanted images based on features related to images, before an image download process; building a website model as a feature source; computing probability a file extension type is related to an unwanted image; and removing the unwanted images from an indexer download list before the image download process. 19. The method of claim 16 , further comprising an act of extracting features related to appearance of an image location descriptor on pages, a host website, and a domain.