Hi,
Are there any ways to avoid or at least to make it difficult for visitors to save a record page and images on his pc ?

No.

You can fool some of your visitors with JavaScripts that will disable the ability to "right-click" on a page (you can even pop up a message telling visitors they can't save items) - but, they are easy to get around. Visitors can simply turn off JavaScipt in their browsers or they can click both mouse buttons multiple times and the right click menu will come up. I've also seen one script that allows you to make a custom menu where you can simply leave off the Save-As option, but it is not fool-proof either.

thanks a lot for your kind help.

some pages are impossible to save -except through source code- for ex :

http://web.amnesty.org/pages/aboutai-index-fra

do you have an idea how they do that ?