I'm fairly sure it was upscaled for this; you wouldn't painstakingly redraw a background like that only to put a blur filter on top so that it has even less detail than the original, unless you were silly in the head.
Also, nice catch. It's been so long since I read Tsukihime that I forgot what that background looked like.
I kinda figured, and now that I look at it further, even the details in the photo on the wall match the game CG. I'll tag it with photo_background then. Thanks.
But you're totally right, it would be nuts to meticulously recreate even the pattern on the sofa just to make it blurry at the end.