Gone are the days when those search engine spiders were busy reading text, now the things are bound to change as it is expected that Google would start reading the images too. if you want to end up being an intelligent internet marketer, make sure that you optimize the images too as the time is not far when Google with start recognizing these and start reading the text within. With the number of digital images increasing on the sites, it is expected that this would be the next change coming in and thus you need to stay prepared.
If you want to make sure that the rankings stay intact even when Google starts recognizing the images, you need to make sure that only optimized ones are present on the website. The image that you choose needs to be in sync with the keyword that you are using as with this the chances of you appearing high on the search engines are going to improve. Also make sure that you do not place a random image that has nothing to do with the content of the page as sooner or later this will come out as a sin.
Google is all ready to understand images, you need to make sure that a correct one is placed at the correct place so that your site gets read and ranked. Make sure that the images are not misleading as with this you will get all negative feedback in terms of rankings.
Source: http://www.searchenginejournal.com/will-google-read-rank-images-near-future/117580/