failed to identify the border points if the geolocation points are in linear towards X or Y

[GMudide]

Hi,

I was using Concaveman to find the border images when the geolocations are not in a specific patern then it work very well but it fails if the points are in sepecific pattern as attached in the image. I tried changing the concavity but didn't work. I was using concavity of 2 and lengththreshold of 0for all the dataset since my data points would of smaller area and closed together.

Attached image is a where sample points are linear towards Y axis.

could you look and suggest.