9. A method, performed by a computer system executing machine-readable instructions, the method comprising acts of: accessing images for download to build an index of search content; prior to download, applying a detection algorithm to image feature information of the images that predicts unwanted images of the images; computing a probability that the unwanted images are of a specific file extension type; removing the unwanted images from an indexer download work list based on the image location feature information, such that removal saves indexer bandwidth and improves an index publish rate; and downloading wanted images for inclusion in the index.
9. A method, performed by a computer system executing machine-readable instructions, the method comprising acts of: accessing images for download to build an index of search content; prior to download, applying a detection algorithm to image feature information of the images that predicts unwanted images of the images; computing a probability that the unwanted images are of a specific file extension type; removing the unwanted images from an indexer download work list based on the image location feature information, such that removal saves indexer bandwidth and improves an index publish rate; and downloading wanted images for inclusion in the index. 14. The method of claim 9 , further comprising detecting the unwanted images after image pages are crawled but before the download.