Image Editing

I have about 2000 images similar to this one. What I want to do is get rid of the distorted, random particles and such that are all around the human body, so that it is the body surrounded by black. I have used the ‘hue correction’ node to get this far, how could I get rid of the rest?


I would suggest using a luma key to isolate the black then the dilate node to overwhelm the dots and rubbish, but when you reverse the effect with erode node you may loose edge definition. However you aren’t trying to key the edges of the cutaway, so long as there aren’t any bits of garbage right next to the cutaway shape it should work ok.

BTW that is pretty creepy cool.

Thanks so much for your reply! As to your suggestion… I am new to the compositing… so I kind of don’t know what I’m doing. My tree looks like this: Image input, going into Luminance Key, going into Dialate/erode, going into file output and composite. Would this be the right setup? And if it is, could you lay out a little more exactly what I do in the Luminance Key and the Erode nodes to get rid of the rubbish outside the body?

there you go, I tried out a bunch of new keyers in the latest build and found that Distance key gave better fine tolerance keys (down in the blacks).

The erode takes a while to compute which is why I linked the scale to the render settings. That way you can test the settings on a small scale first.

Good luck.


test garbage matte.blend (514 KB)

Thank you SO MUCH for this. From that image I’m going to learn a ton about compositing, I know it. And it will help me solve this problem with my images I’ve been having for weeks. Again, thank you!

One more question. In your ‘dilate/erode’ nodes, you have a box next to ‘distan’ that says either step or thresh. When I add this node, I don’t have this dropdown box. I simply have the distance slider value.

It may depend on the version of blender you have. Mine is very recent build from

Nevermind, I found out it’s because you’re using the latest build. Thanks for the help again!