This is a plug-in for converting color images to grayscale. The plug-in allow you to set how much the different color channels will influence the resulting grayscale. You can select to lock the luminance in the image or unlock it to e.g. get an over/under exposed image.
You can download the plug-in here 070515.
Installtion: Place the downloaded file (GreyscaleWPF.dll) in the Paint.NET Effects folder. It will appear in a submenu called Dobu. It will take some seconds to load the plug-in. Be patient.
NOTE: You MUST have .NET 3.0 installed on your computer, download the runtime from Microsoft. This plug-in uses Windows Presentation Foundation which is a part of .NET 3.0.
Edited: Ok sorry, XP didn't like the opacity stuff so after turning it off it should work. I will test it a little bit more but the file is updated so you can try again.
//Anders
http://www.bursjoo.se