3d objects on an image.

Hi.


Ive got a plane with an image on it. It is taking whole screen. Next I want to "insert" 3d Gameobject(human with animation) in it.
My problem is that there is big difference between my image and GameObject so you can see that the GameObject is not on the image. I used two cameras and post proccesing so only my GameObject is affected by the post proccessing (reduce saturation, add tiny bit of blur). I created a shadow for my GameObject.
But no matter what I do I can still see that my GameObject is not on the image. I know it is not possible to make it perfect, but maybe you got any ideas what else I could do?

I think that my problem is debayering. Bluring my GameObject help a little bit. I was wondering is it possible to blur only the edges of the GameObject, maybe with a shader or something?

 

post image