Right, it turns out that the original plug-in is no longer compatible with PDN. I fixed it, and also decided to make it open-source! This way I can take contributions to improve this, and maybe it will also help improve other plug-ins with this sort of alpha handling.
The code is only a few lines of code long, but it uses (*gasp!*) MATH! Check it out if you're the coder type.
The attached zip file includes both the DLL and source code (which you can open with CodeLab).
Hi there! Long time lurker, first time poster. PDN has been my favorite graphics tool for quite some time.
There's the old problem of recovering alpha information lost in compositing, for example when you *ahem* borrow images from the web. Say, smooth edge pixels on a black background; you'd prefer if they were transparent. A few plugins are available, and they do OK 90% of the time, but they fall short in recovering the original color information...
See, it's not enough to figure out the alpha channel. You also have to use it to change the colors so they will look good when compositing again. Otherwise, there would be a visible halo (the color of the background) around the edge. AFAIK this happens with all existing plugins to eliminate backgrounds. So, I decided to make this one.
I've got some pictures to demonstrate the effect and illustrate what I mean about the color correction
Edited by Jotaf, 11 October 2011 - 04:28 AM.