What program did you use to create the X-Ray effect in Sniper Elite?

Question

Game development

Demo (Caution! Image of blood)

How did you create the X-Ray effects in Sniper Elite? And is it possible to create something similar yourself?
And further. What programs were used to create this effect and how difficult is it to create an X-Ray effect?
PS: Google unfortunately could not help me. Searched even in English. Anyway, I couldn't find any information.