Just a question Whilst I have contemplating my navel.
In the binning module , what algorithm is used ?
Thx
Binning
Re: Binning
Hi Andy,
At "perfect" integer ratios (e.g. 2x2, 3x3, etc.) the average is taken of the pixels in such a patch.
However, in all other (fractional) cases, a special resampling algorithm is used that performs downsampling with a custom-designed anti-aliasing filter (a Gaussian filter with some of its second order derivative added, much like this).
The goal of this filter is to make sure that no over or undershoot (ringing) is introduced, as this is particularly detrimental to any subsequent deconvolution of the data.
Hope that helps!
At "perfect" integer ratios (e.g. 2x2, 3x3, etc.) the average is taken of the pixels in such a patch.
However, in all other (fractional) cases, a special resampling algorithm is used that performs downsampling with a custom-designed anti-aliasing filter (a Gaussian filter with some of its second order derivative added, much like this).
The goal of this filter is to make sure that no over or undershoot (ringing) is introduced, as this is particularly detrimental to any subsequent deconvolution of the data.
Hope that helps!
Ivo Jager
StarTools creator and astronomy enthusiast
StarTools creator and astronomy enthusiast
Re: Binning
Thanks Ivo, thats perfect.
I have always used integer bins in the past, and had excellent results,
But with a new focal reducer I am looking at fractional ones now.
Didn’t want to compromise the quality in any way.
Thanks for the reply.
I have always used integer bins in the past, and had excellent results,
But with a new focal reducer I am looking at fractional ones now.
Didn’t want to compromise the quality in any way.
Thanks for the reply.