共用题干
First Image-recognition Software“the Web has evolved from a small collection of mostly text documents to a modern,massive, fast-growing multimedia data set,where nearly every page includes multiple pictures or videos. When a person looks at a Web page, he immediately gets the gist（主旨）of it by looking at the pictures in it.Yet,surprisingly,all existing popular search engines,such as Google or Bing, strip away the information contained in the photos and use exclusively the text of Web pages to perform the document retrieval. Our study is the first to show that modern machine vision systems are accurate and efficient enough to make effective use of the information contained in image pix-els to improve document search.”
The researchers designed and tested a machine vision system—a type of artificial intelligence that allows computers to learn without being explicitly programmed—that extracts semantic（语义的）information from the pixels of photos in Web pages. This information is used to enrich the description of the HTML page used by search engines for document retrieval.The researchers tested their approach using more than 600 search queries（查询）on a database of 50 million Web pa-ges.They selected the text-retrieval search engine with the best performance and modified it to make use of the additional semantic information extracted by their method from the pictures of the Web pages .They found that this produced a 30 percent improvement in precision over the original search engine purely based on text. Paragraph 1______