My advice, If you have specific size for your background for each device, then go for relative layout, and set the background to your image. Because when using background in RelativeLayout, It'll fit the size of the relative layout itself, whether the image suits the size of the RelativeLayout or not. (Can be stretched/pixelated/Not properly added)
If you're not sure about specific size, you should use FrameLayout, with ImageView, that handles the ScaleType, which can be centerCrop, and it'll fit the layout in good shape.
And for the TextView, use layout_gravity, which will handle the position based on the parent layout.