Why Google Images not Indexing Pictures on my Blog

I almost forgot about the referral traffic from Google Images until a few days ago when I checked the traffic stats of my new blog. The visits from Google Images account for nearly 10% of that blog and it is currently the best referral source as well. Then, I came back to check if my pictures have got indexed on Google Images yet by typing site:fun2for.blogspot.com on Google Images search bar. Amazingly, none of the pictures were indexed. My blog is 2 year old and there is no way Google considered it as a new blog. So, what was my mistake then?

Used Some Tips And Solve The Problem

1. All pictures should be hosted on your own server.
2. Make sure your robots.txt file is not restricting Googlebot-Image from crawling pictures on your website.
3. Go To Blogger Settings and click search preferences and Disabled Custom robots.txt.
4. Now Click To Setting - Other Site feed 
5. Allow Blog Feed Full
6. Post Feed Redirect URL ( Remove )
7. Post Feed Footer ( Remove )
8. You Don't Used space In To  Images Name ( EXP : Nice  Pic ) It's wrong . Your Pic Name ( EXP: Nice-pic ) 
9. Resubmit Sitemap And 24 Hours Your all Images Is Index .