Convert color deviation to alpha variation of a single color

[felix-hilden]

Hello, I've made an effect that converts pixels to a single color and adjusts the alpha value based on deviation from that color. Essentially it's a grayscale to alpha converter, capable of extracting black or white objects from a background of the other color, but it could be used with other colors as well. Should the image contain alpha values already, it can be blended with the calculated alpha. The resulting image has only one RGB color, with all variation in the alpha channel only.

 

Download the plugin

Menu: Effects > Color

 

Why this plugin? There are multiple plugin packs (1, 2) that advertise begin able to perform the same task or similar tasks. However, I've found that they do not function quite as I'd like, or maybe I've misunderstood how to use them. Nevertheless, this plugin is as easy to use as it gets.

 

To install, extract the folder and run the batch install file, or locate your paint.net effects and paste the .dll file there manually.

 

I would also appreciate any feedback on the plugin! Maybe you have an edge case for which it doesn't work, or an improvement that should be made.

 

EDIT: Updated and renamed plugin, title and description

 

[Djisves]

Thank you @felix-hilden for sharing.

Reading your description, I thought we would be able to select any of the basic RGB colours to keep. So I'm a bit disappointed that we only have a choice of black or white.

 

The UI for those wondering:

I did some testing to compare with some of the many options available. I used a yellow background to make the details visible at this size: 

EDIT: I forgot to mention that I do like the results!

 

 

Edited January 11, 2021 by Djisves

[felix-hilden]

Thanks a bunch for the feedback @Djisves! I updated the plugin to be able to select arbitrary RGB colors as the solid. I'm not sure why the examples you provided are much lighter in some places, likely because of the additional parameters doing something... additional, or that the deviation is calculated differently. In any case, much appreciated!

[Djisves]

This is a lot more like I thought it should be. Thank you.

In the examples below I used a black background so the less of the colour selected a pixel contains, the more black shows through. 

 

 

[Ego Eram Reputo]

Nicely done Felix. I've taken the liberty of adding the menu location & an image of the new UI. 

 

I recently added to the guidelines to publishing plugins. The changes I made are in accordance with items 5 & 6 in the second post.

[felix-hilden]

Thanks a bunch @Ego Eram Reputo! I'll make sure to follow them with my next release.