Now you can optimize your major images through site .Google now support images in site map .
Image tag is
<image:image>
<image:loc>
</image:loc>
</image:image>

Read the full article at: http://googlewebmastercentral.blogsp...-sitemaps.html

What you think , now with text link promotion , Image link promotion is also get higher value to get good position SERP .

that is really,if is true,that is good news for me,thanks for shared

The sitemap is just a list of your pages in a solo page layout. When a caller goes to your site they can right to use the sitemap to discover any pages that they are concerned in viewing. typically the sitemap is to benefit the people who stay your site and give them a quick and easy way to navigate your site.

Do you mean its possible now to optimize images in addition to adding alt attribute to them?
And can you explain more what are the codes you have written?
I didn't understand the meaning of these codes and the way we can optimize images using them.

That is a good information from Google.

This is surely a big hit for Google's much better indexing of images, especially for photo and gallery-oriented sites. Good thing the new interface of Google image result loads so fast...