Change to my site to block google image to show full image size

Hello - as you all know google is not the webmaster friend anymore, they have now changed there image search so people dont have to go to a website. I have seen a site who had made a good solution for that problem : Try a search on Google image for site:[login to view URL] I was told it was done with this .htaccess and PHP+GD Library is applied to achieve the function, + functions as imagecopymerge() was a big one in recreating the opacity overlay! The point is I need a solution so google dont grap my large images, so a google image visitor has to go to my site to get the large resolutions. The same problem is with Bing image, before i had a frame breaker, but that dont work anymore.