This effect discards middle parts of the image to make it require less space. Main purpose of this effect is discard the unnecessary parts of the image to effectively use that image in sprite atlas. This way you can use the image with 9-sliced technique without any loss (such as used in Unity).
I was tired of manually doing this over and over again (you have to modify most of the game assets published in the internet to pack tightly in sprite atlas). And it is time consuming to make all the border size's consistent. Since Paint.NET stores last used effect parameters, you can make every sprite consistent (Same size as the previous sprite)
Preview
How to use
Download the plugin NineSlicer.zip
Extract the zip file
Install into Paint.NET (Either double clicking "Install_NineSlicer.bat" or place "NineSlicer.dll" in "Effects" folder, by default it should be located at "Program Files/paint.net/Effects")
Open Paint.NET and go into Effects->Object->Nine Slicer
Parameters
Left: Left border size
Left-Right Symmetry: If checked right border size will be equal to left border size
Right: Right border size (You have to uncheck Left-Right Symmetry to change this parameter)
Top: Top border size
Top-Bottom Symmetry: If checked bottom border size will be equal to top border size
Bottom: Bottom border size (You have to uncheck Top-Bottom Symmetry to change this parameter)
Source Code
License CC0 1.0 https://creativecommons.org/publicdomain/zero/1.0/deed.tr
