DuckDuckGo’s Image Search is now a very pleasant experience in terms of relevancy ranking, a year after introduction of the images service in the summer of 2014. Speedy, too.
Of course it lacks Google’s useful filters for Creative Commons and image-size, but CC can be approximated in DuckDuckGo by adding the keywords Commons and Attribution to one’s search — and DuckDuckGo doesn’t seem to distort such a search by also trying to finding synonyms.
Nor does adding the word commons mean that it get confused into searching for pictures of the ‘heather and hawks’ type of natural heathland commons.
Such an approximation of CC appears to work quite well. And in such cases (‘find large-size CC images’) DuckDuckGo doesn’t appear to have a major handicap compared to Google, since both search engines seem to cover the same mega-services such as Wikipedia and DeviantArt etc.
Flickr is a special case, since the relevant keywords aren’t there — one would do better to use search.creativecommons.org for a thorough CC Flickr search.