I've been dealing with taking screenshots for Firefox and Safari browsers but I can't figure out how to do it! With Google Chrome API I can do it this way (it's pretty simple):
chrome.tabs.captureVisibleTab(null, null, function (image)).....etc
BUT I can't find a SIMPLE way to do it on Firefox and Safari!! The only answer I got here was using the 'html2canvas' (http://html2canvas.hertzen.com/examples.html) BUT IT IS NOT a 100% solution in order to take EXACT screenshots of a specific webpage!! It doesn't work for me in this case!!! Can someone help me with this issue in order to find a simple solution for Firefox and Safari?
I have personally used html2canvas and I found it quite efficient for taking partial or full page screenshots. But it does require you some knowledge of JavaScript and client side scripting.
If you are looking for a more easier approach , there are numerous extensions on Google Chrome webstore. A popular one is Awesome Screenshot which even allows you to take screenshot of entire webpage (till the scroll bar ends).