Image Search can be a very useful tool you for you to find just about any kind of images you want, however, it can be difficult to find the right image that you really want if you can’t describe it in words, or the name of an image file on a website is not probably described leading it to be unsearchable in the Google image search engine.
Just few months ago, Google launched another new experimental feature via Google Labs that allows users to search for similar images among those image results using the Google Similar Images search. Users can easily find images that look like an existing result just by clicking on a “Similar Images” link underneath those images.
For example, if you search for “apple”, maybe those search results will be a mixture of some apple computer products and some apple fruits, so you can use the “Similar images” link to quickly narrow down your search.
Checkout: Google Similar Image Search