PNG inside Engine takes a lot of memory

As normal png it takes ~77kb, when i import it in unreal engine 4.8 it shows that it uses 21mb. How to reduce that size inside ue4?

Update: Only when compression is set to userInterface2D which i need for UMG. On Default compression it take 5.6MB. This is on texture size 2048x2048 (yeah i need that big texture (if texture is 1024x1024 or lower i need to scale it up which looses a lot of quality))

Due to the large volume of questions and comments concerning the Engine, we did not have a chance to respond to your post at the time you submitted it. However, if you are still interested, the following documentation describes how to optimize textures when creating a UI with UMG:

UMG UI Designer User Guide

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