Add all touched parameter to RS_ZonalStats

[VtotheG]

I want to use ZonalStats (https://sedona.apache.org/latest/api/sql/Raster-operators/#rs_zonalstats) for my use case of integrating polygons of buildings with information from a tif file.

In the past I used the rasterstats library to get the info in python, but i have a lot of buildings and wanted to use the power of Sedona. When I look at rasterstats it has the property all_touched which determines if the pixel should be included in the rasterstats calculation see; https://pythonhosted.org/rasterstats/manual.html#zonal-statistics.

Actual behavior

The current RS_ZonalStats function only returns the value of pixels that fall within my polygon. This causes a lot of issues when the houses / buildings are quite small (it will return a NaN because non of the pixels are fully encapsulated by the polygon.

Steps to reproduce the problem

Example of the usage
results = sedona.sql('''
select 
id
, geometry
, RS_ZonalStats(r.raster, a.geometry, 1, 'max', false, true) as max_elevation 
from buildings a, tifmap_with_elevation r
where 
RS_intersects(geometry, r.raster) 
'''

It would be great to have an additional parameter which would indicate if RS_ZonalStats should only summarize the statistics of pixels within the geometry or all pixel that are being touched by the geometry

I thought that adding a buffer with the size of my pixels would solve my issue, but i think it is then still possible to grab pixels which should not be part of the calculation.

Settings

Sedona version = 1.7.0

Apache Spark version = 3.5.0

Apache Flink version = ?

API type = Python / SQL

Scala version = 2.12

JRE version = ?

Python version = 3.11

Environment = Databricks

[github-actions]

Thank you for your interest in Apache Sedona! We appreciate you opening your first issue. Contributions like yours help make Apache Sedona better.

[jiayuasu]

We are aware of this and we are working it now. CC @prantogg