How can I have bigger imageview for larger screen size layout?

I am looking at my android design for medium and large screen. I have designed my layout for mdeium screen (viewing it on the eclipse editor and emulator) and making sure it is good. My design involves textview and images view. I have create the 3 drawable folders for different density sizes so the picture can occupies the rough space on different densities.

Now, I am looking at the large screens (and even xtra large screens) but my textviews and images views looks very small (compared to the size of the screen). Therefore I would like to make use ofd the extra space by enlarging everything.

I know how to do it for text views, basically I would make textsize bigger (ie. instead of 12 sp I can make it 16sp)

But How can I do it for ImageView? The Imageview displays the image according to its size. And the size of the image is really meant for medium screen. How can I make it bigger? Should I provide the same image with a bigger size and a different name?

Please help, btw plz dont point me to the android develoment supporting mutliple screens cause I read it and I couldn't find what I need unless I missed a certain line that answers my question.
Thank you for your help

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