Weird white outline on ImageGuis

Bug Reports Engine Bugs
#1

I noticed that when an image gets to a certain size, something very strange happens visually.
blob.png
As you can see, once the image resolution is lower than the gui size, the image become blurry which is expected.
Each of these imagelabels are 100x100 while their image resolutions vary. However, when the image goes a certain size, a strange white outline forms. Interestingly, changing the ImageColor3 does in fact change the color of it.
blob.png

#2

This is due to the decal system, and not the ImageGui system, no?

#3

Both actually.
You can replicate this with basically any form of images, even textures.

#4

Should go into Client Bugs, and also it would be a good idea to enclose a (minimal) place file which has the texture that you’re showing here and shows the issues in the UI.

#5

Just a link to the asset would probably be fine. That being said, I’m fairly certain ROBLOX already knows about this issue. I think discussion of it came up back when they fixed the issue with black lines around transparent image borders and they said something along the lines of “this is difficult to fix”.

#6

AFAIK this is not an issue with roblox, but rather the image editing software you use (in combination with roblox not using special countermeasures to prevent it).

You need to ensure even the invisible pixels are colored the correct color. If you just ignore their color (and simply make them transparent), leaving them white (or any other color), that color will bleed into the visible parts of the image when the colors are interpolated when sampling the texture for rendering.

You can sometimes do this manually (just color the pixels regularly, except transparent of course). I assume there exists software to do this automatically. I read some image editors will ignore color for fully transparent pixels tho, just have to use a different editor in that case.

There is a way to implement transparency that avoids the issue, but its not the ‘default’ way to do things I dont think (“premultiplied alpha”).

1 Like
#7

Is it this?
http://devforum.roblox.com/t/how-to-get-rid-of-white-outline-paint-net/24336/10

#8

No, the issues are separate. The issue in that thread is whoever was editing the image didn’t clean up the edges of images entirely properly. The issue in the OP is white lines appearing when images are scaled down to be really small.