In Firefox, hold down Shift while you right-click to get the menu. No doubt something similar on Chrome, but not sure it'll be the same key.
Or when you right click first time, you will get message saying "copyright protected, blah blah".
Acknowledge it by presiing okay, then right click again... same message comes up, but this time you select the box that then prevents same message coming up.
so when you right click the third time, "searxch image on google" comes up as one of the choices.