I have a set of points (one to many) in polygon. The middle polygon has a lot of concentrated and correlated points. Looking to see if there is way or an algorithm within QGIS to reduce the number of points, for lack of a better word reverse interpolations.
You could try the SAGA tool named Points thinning which is accessible in
QGIS Processing Toolbox | SAGA | Vector point tools | Points thinning.
A picture below shows (a) randomly distributed (100) green points , which then (b) be reduced to (48) red points by Points thinnging tool.
There is a parameter to be set,
Resolution (default value: 1.0). In this example I set
500. The meaning of this
Resolution will be understood looking at (c) green circles (250m radius) underlying the thinned red points.