The search giant has altered the algorithm for image search to bring it in line with its web and video searches, which filter out pornographic sites unless the user is clearly searching for them.

The change applies to the 'SafeSearch' setting, which is designed to stop images of violence or sex displaying in search results. The number of options has been reduced from two to one, with 'filter explicit results' either on or off.

As of this morning the changes only applied to those searching Google in the US.