How to change .tif resolution of a raster file without data loss

Question

For example, a .tiff file of size 400 * 200, I can read it as a two-dimensional array (400 x 200) in Python.

I want to change the tiff size to 200 x 100 or another ratio.

How to implement this in Python or GIS software (QGIS, ArcGIS et.al).

I know that a tool reminiscent in ArcGIS can resize raster data. but the ratio of length to width is fixed.

Example Chart:

_{(source: tietuku.com )}

Answer 1

With R, you can do things like

library(raster)
r <- raster('file.tif')
a <- aggregate(r, c(2,3))