I want to resample a raster from 15m to 460m using a Gaussian filter.
I am having a coarse image which I want to downscale. I also have a fine resolution band to assist the downscaling. The downscaling method I am using is called geographically weighted area-to-point regression Kriging (GWATPRK). The method consists of two steps:
- area-to-point Kriging on the GWR's residuals
In order to perform GWR using raster data, those needs to have the same pixel size. This means that, my fine resolution image needs to be upscaled to match the spatial resolution of the coarse band. This upscaling of the fine band needs to be done using a Gaussian kernel with $\sigma = 0.5$(i.e., the PSF).
How can I upscale (reduce the spatial resolution) a satellite image using a Gaussian kernel (i.e., point spread function)?
For reference, I am following the paper The effect of point spread function on downscaling continua where the authors at p.253 in Eq (9) mention:
the coarse image produced by upscaling the corresponding fine band k using a PSF.
I googled how I can achieve that but unfortunately I couldn't find any solution. So to do this, how can I use this Gaussian filter to change the resolution of my image with
Here is the image I am trying to convolve: