in my app I have to compare two images, so I found this code.
I tried on my localhost and work fine but I have to do the same on appcelerator and I have some errors, the first is on var img = document.createElement('img');, then on getContext.
is there a way to adapt the code to titanium?
First of all, Titanium is not HTML so you cannot use DOM things as that code does. Though you can use Javascript but Titanium has its own sets of API and it is really superb and broad. Look here to know what you have got under the hood in Titanium
You have to look into many APIs to make your task done, but first you need to understand what that code is trying to do and what you want to achieve because if you understand the logic, then you can do it in Titanium as well. But please do not adapt DOM or HTML to Titanium :)