Build your sitemap: Image sitemaps

With Image Search, just as with Google Web Search, following Webmaster Guidelines and best practices for publishing images can increase the likelihood that your images can be found in Image Search results. Additionally, you can use Google image extensions for sitemaps to give Google more information about the images available on your URLs. Image sitemap information helps Google discover images we might not otherwise find (such as images your site reaches with JavaScript code), and allows you to indicate to Google images on your site that you want Google to crawl and index.
To give Google information about images on your site, you'll need to add image-specific tags to a sitemap. You can use a separate sitemap to list images, or you can add image information to an existing sitemap. Use the method works for you!
For each URL you list in your sitemap, you can 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.

 
 
   http://example.com/sample.html
   
     http://example.com/image.jpg
   
   
     http://example.com/photo.jpg
   
  
 

You can list up to 1,000 images for each page, using the syntax outline in the example above!

Image tag definitions

Tag	Required	Description
	Yes	Encloses all information about a single image. Each URL ( tag) can include up to 1,000 tags.
	Yes	The URL of the image. In some cases, the image URL may not be on the same domain as your main site. This is fine, as long as both domains are verified in Webmaster Tools. If, for example, you use a content delivery network (CDN) to host your images, make sure that the hosting site is verified in Webmaster Tools OR that you submit your sitemap using robots.txt. In addition, make sure that your robots.txt file doesn’t disallow the crawling of any content you want indexed.
	Optional	The caption of the image.
	Optional	The geographic location of the image. For example, Limerick, Ireland.
	Optional	The title of the image.
	Optional	A URL to the license of the image.