10. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: receiving a web page that includes text and images; selecting a first subset of the images that are not excluded content-type images, wherein an excluded content-type image is an image that is boilerplate content or that is advertising content; determining, for each of the images in the first subset, (I) whether the image has a size ratio that is within a predetermined size ratio range, (II) whether the image has greater than a predetermined quantity of pixels, or (III) whether the image is located between a defined minimum altitude and a defined maximum altitude on the web page; selecting a second subset of the images in the first subset based on the determinations for the images in the first subset; determining (i) a quantity of images in the second subset, and (ii) a ratio of the area of the web page that is covered by the images of the second subset to the total area of the web page; generating a score for the web page based at least on (i) the quantity of the images in the second subset, and (ii) the ratio of the area of the web page that is covered by the images to the total area of the web page classifying the web page as a gallery web page based on the score for the web page meeting a predefined threshold; and based on classifying the web page as a gallery web page, formatting a search result that references the web page, among a set of search results that each reference a different web page, using a search result format that is designated for web pages that are classified as gallery web pages.
15. The system of claim 10 , wherein the operations comprise: labeling the web page that is classified as a gallery web page, as a gallery web page.