Now you can use a Sitemaps extension to provide Google with exactly this information. For each URL you list in your Sitemap, you can add additional information about important images that exist on that page. You don’t need to create a new Sitemap, you can just add information on images to the Sitemap you already use.
With image search, just as with web search, Google's goal is to provide the best and most relevant search results to our users. Following Google's Webmaster Guidelines and best practices for publishing images can increase the likelihood that your images will be returned in those search results.
every page might feature a boilerplate image. By not listing this image in your Sitemap, you're telling Google that it's less important than the images you have included. However, Google doesn't guarantee that we'll index all of your images or use all of the information in your Sitemap.
To give Google information about images on your site, you'll need to begin by creating a standard web Sitemap. (You can also update an existing Sitemap.)
For each URL you list in your Sitemap, add additional information about important images on that page. The following example shows a Sitemap entry for the URL http://example.com/sample.html, which contains two images. (You can list up to 1,000 images for each page.)
<?xml version="1.0" encoding="UTF-8"?> <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:image="http://www.google.com/schemas/sitemap-image/1.1"> <url> <loc>http://example.com/sample.html</loc> <image:image> <image:loc>http://example.com/image.jpg</image:loc> </image:image> <image:image> <image:loc>http://example.com/photo.jpg</image:loc> </image:image> </url> </urlset>
Image tag definitions