Well, hmm, I wouldn't really say that. You can put it as, "Pensons aux victimes de la guerre." => "Let's think about the victims of war".

"Think of the children!" => "Pensez aux enfants!"

I don't know chinese, but if 认为 translates to "consider", it could work in that context. "Consider the children."; "Consider the victims of war".

Maybe it's hard to associate it with that meaning because of subconscious association with Apple's "Think different", which is definitely closer to "Imagine".