I am currently discussing a design scheme with a friend of mine who is a designer. And i don't know at what resolution i should tell him to make the background image. I was thinking of telling him to make a high-def image and then go from there, re-scale it for smaller device screen, but i don't know and am not able to find online which resolution is the highest.
Tell him to check out the Android design pages and all the related links on that site. It tells everything you need to know about Android design principles.
Other link(s):
Quote from the Devices and Displays Page:
Strategies
So where do you begin when designing for multiple screens? One approach is to work in the base standard (medium size, MDPI) and scale it up or down for the other buckets. Another approach is to start with the device with the largest screen size, and then scale down and figure out the UI compromises you'll need to make on smaller screens.