Interpolate the polygon for frame sequences

[sykrn]

Is your feature request related to a problem? Please describe.
Let us have a frame sequence aligned in a folder. It will be great if we have interpolate position for each polygon, so that we don't have to label each of them.

Describe the solution you'd like
It is a simple thing to do in python using convex combination, however for QT integration needs several components.
The solution is we can track a polygon at a start frame and a stop frame, then we can interpolate using convex combination formula:
for each point in polygon we do:
$P(t)=P(start) + t * P(stop)$

However, it's just an idea, I don't know it can be integrated to the GUI apps.

I saw this feature in Darklabel. However, they have limited features compare to labelme here.

Thank you very much.