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Polygon Mask leaves an outline (RESOLVED)


Adamu

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HI

OK. Although you haven't said so it seems you are masking an object on an upper clip/image with a transparent exterior and then playing it over a lower video/image.

I can see you have a line there but not sure why. Increasing the feathering value increases the grey line and I think this is a bug. It seems that feathering is not working correctly as IMHO it simply render the edge either sharp (feathering =0)  or gradually transparent with the clip/image beneath. This isn't happening.

I have notified NCH that this is a possible bug.  Can't think of a way around this.

Nat

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Hi Borate

This is the result where there is a clip with boats on Track 2 with a mask roughly drawn around one boat. The area around the mask is made transparent. It's not for moving the boat it's just to check what is transparent..

bb.jpg

On Track 1 is another clip. The mask is moved to the upper right and the feathering set at maximum....

ab.jpg

It's easy to see (at least here) that there is a grey outline around the masked overlaid object. This can be made to vary from 0 (barely visible) up to an obvious shaded area. It seems that the "gradual transparency" around the edge produced by the feathering is not executing correctly. It's also more obvious when the "object" is placed against a lighter area. The object (the masked area) should just fade out at the edges . It doesn't.

Nat

 

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Hi

Alpha blending problem. ..and yes, NCH checking it out.  There isn't a work around until it's fixed apart from not feathering although it's still there. Try it with near identical colours. like the blue sky here..(Mask outside/feather 0) i.e. use the same image. Even with feathering set to 0 there is a thin grey line..

aa.jpg

Feather set at 0.5.....

bb.jpg

Try this with a white blank over a white blank. With the feather set to 0 and with no diagonal  edges the object edge is invisible  Diagonal edges however show up as thin grey line....

ccc.jpg

Now increase the feather to any value above 0.  ALL edges become visible. Feather = 0.5 in this white on white example....

ddd.jpg

Nat

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