Android : Different density images in Cordova

I am trying to develop an app for both iOS and Android using cordova.I am trying to use the different density images for different android tablets by putting those images under "platforms/android/res/drawable" "platforms/android/res/drawable-hdpi"...etc.

No I am not sure how to refer the appropriate images from these folders in CSS file.The CSS is common for iOS and android.So I guess there should be a general way to access resources for both iOS and android.Please suggest..

Thanks in advance..