Background image of a row responsive 100 %

Hello, I have a line on my page that contains a photo background, to reduce mobile version of the photo background is adapted displayed only part of the picture, for example in the mobile version gets only a central part of the picture and side unseen. I want the screen is reduced according to that picture will adapt by becoming smaller , that is , I want the picture to fit the screen but you still see the whole picture , to look smaller but whole . As if I had a width 100% and go adapting