如何在android studio中将背景图像设置为线性布局而不是颜色？

I am trying to set a background image to a linear layout but cannot figure out how to, now it seems like it's not possible. Is it? if not is there a work around? I currently have a colour which looks quite plain, I am looking to get it patterned i.e. check box etc. would android have a built in thing that allows me to replace the colour with some pattern?I am trying to set a background image to a line