Good practice for drawable resource scaling

Question

I am facing a problem with the size of the generated apk for my app...

I was wondering if there can be any issue if I use only the xxhdpi folder for my drawables... I know that there can be some problem with 9 patch drawable but I don't have any.

The system should take care for scaling down my images, right? Are there other effects that can be dangerous?

Answer 1

1. Yes, system takes care for scaling, but scaling at runtime can affect your app's performance, especially when the scaling factor is not power of 2.

2. Normally scaling down a image wouldn't cause quality problems. however, it may produce a minor impact on image quality under some circumstances, here's a test:

   image in xxhdpi folder, left side is how it looks like on a Nexus 5 (xxhdpi), right side is how it looks like on a Nexus 4 (xhdpi).

3. If image size is less than 4px, app may crash when scaling down.

Conclusion: if app size is more important than problems above, then you can put all images in xxhdpi folder, except the small ones.