What dose the size of the sprite shown in the Editor mean?

We noticed that Unity Editor is reporting image sizes that are WAY bigger what they actually are. We are trying to figure out why, and if we are doing something wrong is bloating out our image.

For example, here is one of our images "skeleton.png", and it shows a size of 145KB on our Mac Finder:

But from the Editor, it shows up as a whopping 5.3MB! We didn't change the image size from what it is on the disk, nor did we change any import settings. MipMap is being auto-generated, but I believe that should have only added about 30% to the size.



So, what's going on? We are particularly interested in what this means in terms of how it impacts the size of the app we build? How it impacts vram usage?

Many Thanks!!

 

I just realized that by changing the Compression Option from "None" to "Normal Quality" or "High Quality", the size shown is reduced down to 1.3MB. Crunch Compression further reduce it down to ~134.6KB even at 100% quality!

What's not completely clear to me is does this refer to the amount of space taken on the disk (impacting the build size), or does it refer to the amount of texture memory used?

 

(1024octet * 1024octet * 4.rgba)+30% =5.3248MB

 

Got it. So it is the uncompressed size of the sprite. thx!