I think everyone who can and have time to help you is already wrote in this topic. I really like to help but I don’t know the problem and I don’t want to come here and only write “I don’t know. Just for information” just how I just did. 
I’m sure there are lots of users here with HTML5 experience here, but they don’t know about the image smoothing.
I made an HTML5 game, but I never needed to unsmooth my images.