Android picture adaptation, drawable folder, low resolution picture is necessary

We know that Android offers several different resolution bitmap to match the density of different phone screens. The corresponding relationship is as follows:

• xxhdpi:3.0
• xhdpi:2.0
• hdpi:1.5
• mdpi:1.0
• ldpi:0.75

So a problem arises:

Since Android can be converted automatically, why waste user space to store low-resolution images when it comes to Android development?

Looked up some information and finally found the answer on Google's developer website:

Note: Low-Density (ldpi) resources aren ' t always necessary. When you provide HDPI assets, the system scales them down by one half to properly fit ldpi screens.

(link:http://developer.android.com/training/basics/supporting-devices/screens.html)

The idea is that low-res resources are not always necessary, and when you provide a high-resolution resource, the system scales the image to fit the low-rate screen.

This is the answer to the question.

There is a question: if the low-resolution image is not placed, so that the system needs to automatically convert, whether the response speed (the system will be cached)?

Android picture adaptation, drawable folder, low resolution picture is necessary