Removing objects from the background

JohnJ wrote on 1/24/2016, 12:09 PM
I have a clip of a train moving across a scenic background. In this background there is an object I have removed using a bezier mask. I have created a lower video track with something more suitable which appears "through the hole". The problem I have is that when the train passes this point the infill is superimposed on the train. I don't know if it is possible to overcome this but I would be grateful for any advice. As this is my retirement project and I do not have great technical knowledge it may be too complex for me but I'm willing to give it a shot.


john_dennis wrote on 1/24/2016, 12:50 PM
Have you considered splitting the clip into three segments using the "s" key?

Segment 1 = Mask Present

Segment 2 - Delete Mask at the first frame where the train appears at the edge of the unwanted background item.

Segment 3 = Mask Present at the first frame where the train leaves the edge of the unwanted background item.

I'm sure you could accomplish this by key frames but it would take longer to describe.

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Tim Stannard wrote on 1/24/2016, 4:54 PM
I think you've made it a little more difficult on yourself by putting the "main video" with a hole on the upper track.
Whenever I do this I do the reverse: Put your "main video" on the lower track and the piece you want to "cover" the blemish on the upper track - so rather than filling a hole that you created with a mask, you are "papering over" the "blemish" with a bit of "paper" that you have created using a mask.
It then becomes fairly simple to keyframe the shape of that mask as the train rolls into it, then move the mask (or make its opacity 0%) whilst the train is over the "blemish", then turn up the opacity and keyframe the mask again once the train has passed.
Rory Cooper wrote on 1/26/2016, 4:45 AM
use a difference mask. take a snap edit remove glitch = use this as a backdrop

Tim Stannard wrote on 1/26/2016, 10:18 AM
Great "how to" by Ron Scott (and it is a "how to" rather than an explanation) Thanks for the link. Not sure about your suggestion though if I've understood correctly - a still image for the backdrop?
Rory Cooper wrote on 1/27/2016, 12:35 AM
yes you can use a still that has been edited as a back drop where the camera was locked down and you want to remove something in the background. so much depends on your original clip.
Boris Red does the same and in older versions of Vegas works on the timeline as a plugin
has a motion key that will remove objects from the clip but the image behind is static
behind the mask
Grazie wrote on 1/27/2016, 2:59 AM
I've used the still image technique to eradicate a visually distracting, annoying plastic vertical blind that was gently flexing due to a draught. Very simple but effective.

JohnJ wrote on 2/1/2016, 5:05 AM
Thank you everybody, I managed to do it successfully