Google Index Image via Sitemaps

"Google Sitemap Generator is a server plug-in that can be installed on both Linux/Apache and Microsoft IIS Windows-based servers"

As you know, the sitemap is considered as a map of any blog / website does. This map will help the robot of Google or any search engine that knows the way to your blog and of course when they know it will collect all relevant information only. No sitemap like you go to a strange city street without knowing it. 

Previously, search engines often rely on the tags, title or caption that you set for your images to search for that photo or image related. However, Google has several times been duped by the rules they set, such as the search keywords children from adult images. Thus, the introduction of new rules based on Sitemaps is completely logical.

Google Webmaster Tools blog has been quite clear if the benefits of including more Sitemaps for photos. It not only helps the robot in the right direction, but also helps you to optimize traffic to your blog. If a page has multiple images, you will certainly see picture prioritize what is most important to arrange the export to Google search results on the SERPs.

According to Google's guidelines, you should insert the following code into your blog: 

<?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> 

If you are still not clear how the operation of this feature, you can easily see the instructions at the Google Help Center.