I hope that someone can help me with this problem.
When I export sequence of PNG images(with transparent background) from Poser I always have thin white outline over objects. I thought this is small resolution issue so I used bigger resolution. I use firefly render and NO I DON'T use outline option. After applying bigger resolution render, outline is barely noticeable, but now instead of transparent background there is always full gray background. I use FireFly option render over current shader, not background colour or background image or over black color.

Now when I check exported image properties it says it has 24 bit depth?!
How to switch back to 32 bit depth PNG image???
I have simply doubled resolution output settings, and now I can't fix this.
Anyone have idea?
THANK-YOU!

I do it by exporting the png, selecting the background with majic wand , and then hit delete. The thin white line may be antialiasing.

I think this might help. In a previous post this week, bagginsbill explained why this happens. Without paraphrasing is detailed and wonderful explanation, the short answer is to choose the option "render over black". Briefly, it has to do with the edges of the rendered object blending with the character to produce a color that it not truly invisible and not truly the color of the object and that's what the edge is.

If I didn't explain this correctly, I apologize. But I tried it and it worked.

SOLVED

Thank you for your reply.

The thing is, it doesn't, work in my case, since I have exported 250 slides as PNG images. It is animation and not a still rendered image. It has no sense to manually fix background of all 250 slides. I have stayed up all night trying to resolve this, and I have found out that resolution must be higher. Much higher. I also tried exporting animation with green background and then I was using AfterFX to remove background. The difference is minor. The solution is to at least double the resolution size and so the rendering time also... :(

Yes- it is anti aliasing.

What I do is render over the background I want to use at the backgrounds dimentions, in the same spot the png will be placed. (snap to).

For me the advantage is that I get the rendered image nice and clear free of borders. While still useing the higher quality background without any pixaliation.