As well as Safe Search option is available for Search Engine Image Results filtering, you can block such results at all with SafeDNS. The following is a list of domains and subdomains that popular search engines use to host image search result content. Blocking these domains and subdomains will block image search results on their respective image search engine.
Google: Google embeds images as data in the HTML source, which cannot be blocked by SafeDNS unless you block google.com as a whole. As an alternative you might try using Google SafeSearch.
Most image may be blocked by blocking the following: