You can go ahead and clear the background only when you have a correct picture.
Making a white background is not that hard, but it takes time and patience.
But don't worry, there is a solution: visafoto.com . It automatically fixes passport photos background and makes it right up to the requirements (typically white, but for some types of passports it could be grey or even red).
Visafoto.com knows all the passport photo specifications for various countries and among other thing does the background.
So if you have your photo ready, you can convert it to a correct passport or visa photo right now at visafoto.com.