Soft-edges between cropped video source and static background image?

[AKoch]

[I had asked this in the plugin ideas forum, but did not get any reply. Before giving up, maybe someone has an idea how to achieve this without a new plugin.]

Hello all,

what is the recommended way to quickly get a soft-edge between a cropped video source (in my case, green screened) and the regular static background?

Without the soft-edges. I get a visible vertical boundary between the green-screened image and the regular background picture. I have not been able to remove that by fiddling with the Chroma Key parameters or changing the lighting.

I think that this boundary could be easily hidden if there was a way to easily create blurring/feathering/softening of the edges between the green-screened video source and the regular static background.

I am aware of using alpha masks to accomplish this. However, the video sources I work with are often cropped on-the-fly to fit specific camera angles, and it would be quite laborious to re-generate an appropriately matching transparency mask (e.g. in Gimp) every time the cropping selection was changed.

Any hints how to achieve this would be appreciated!

 

[novelscale]

I feel your pain, and didn't find any solutions yet. The visible vertical boundary kinda impossible to "remove", been trying with any kind of key and lighting, deleting pixels from the mask etc - no way. Probably the best Idea is to a put a blanket in the back of the green screen to avoid the big gaps in color between the screen and the wall (?).
And yes I recreate the mask everytime, it takes me about 5 minutes since I fixed my webcam

did you find any other solution ?

 

[devin130]

I think I know in theory how to solve your issue. instead of applying the green screen to your image source apply it to a scene (let's call it Scene B), in your scene A add a shape you can move around quickly (e.g. a square) with a green to negative gradient. then in in scene B pull in Scene A as a source and use your chroma key on the whole scene.

tada!

 

[novelscale]

can you elaborate on the "shape with a green to negative gradient"
I get the shape/mask part and the scene stuff, just not sure what you mean with green to negative gradient / green to black ?
green to alpha ?

thanks

 

[devin130]

Alpha (video term)=negative (image term), they equate here. You want to go from green to "nothing" to fade into your subject I created a png for you to demonstrate cheers!

 

[devin130]

Alpha (video term)=negative (image term), they equate here. You want to go from green to "nothing" to fade into your subject I created a png for you to demonstrate cheers!

**correction**, my use of the term negative is imprecise here, fuzzy morning lol, apologies, the term "transparent" instead of negative would be better.