title: image size to avoiding of going to blurry in android
body: <p>i have some problems with images and icon's in my android development. some times my images and icon's goes blurry and does not crisp and sharp. now i want to do this:
  i create a 960px x 720px image layout in Photoshop and create my interface in it. for example buttons etc. and put that image(UI elements in the hdpi folder) in this way i see them in my nexus 4 in nice condition but its not perfect crisp and sharp images. and then for some images that goes to bad quality in small phones due to scaling down, i want to create a smaller size of images and put them into the ldpi folder. is this a right direction? how can i calculate right dimensions for 4 main screen sizes? i s this a good choice of creating my main layout in a 960px x 720px layout size? for example when i create my layouts and icons in  480px x 761px all of images and icones goes to blurry  in my nexus 4! please help me to pass this obstacle.</p>