When you're searching for images in Google, sometimes it can be hard to come up with exactly the right words to describe what you have in mind. To make it easier for you to find images Google added a sorting feature to its images search engine.
For example, when you search for [london], by default you'll see image results ranked by relevance. Click on "Sort by subject" in the left-hand panel and you?ll see images organized into categories that will narrow down your search and help you find the exact image of London that you want.
You can also use this feature to explore categories of a general topic that may be easier to learn about visually, like flower varieties or dog breeds.
Sorting by subject uses algorithms that identify relationships among images found on the web and presents those images in visual groups, expanding on the technology developed for Google Similar Images and Google Image Swirl. By looking at multiple sources of similarities, such as pixel values and semantic relationships, and by mining massive amounts of data, Google can make meaningful connections and groupings among images.
Sorting will be rolling out globally to nearly every domain and language over the next week.