Android: Designing Different Icons for Screen Densities

I know it's good practice to design different menu icons for different screen densities. I read that the preferred size for the different densities are:

• 36 X 36 px for low
• 48 x 48 px for medium
• 72 X 72 px for high

I want to avoid doin开发者_如何学编程g unnecessary work. Is it a good idea to design just 1 icon at 72 X 72 px, and just use that, and have Android do the resizing automatically? I don't see how that's any different than me resizing it and creating 3 separate images?

The benefit of having different icons is that you have control over the final appearance, rather than allowing an algorithm to munge your image. Few scaling algorithms are able to maintain quality when reducing an image's dimensions, especially for complex icons.

Be sure to read Android's scaling rules, and also this page has an excellent investigation into image scaling and its effects on the final image.