[cairo] Pixels Are Not Little Squares

[Lawrence D'Oliveiro]

I wrote:

> On Fri, 22 Apr 2016 13:22:19 -0700, Krzysztof Kosiński wrote:
> 
>> The little square model is OK for Cairo, since it uses a box
>> filter...  
> 
> Just in case there is any confusion over this point, the “box” shape
> for a filter is the shape in the frequency domain. In the sample
> domain, the dual of this is the sinc function, which looks nothing
> like a little square.

Hmm, maybe this depends on your interpretation of “box” ... the common
interpretation nowadays seems to apply to the shape in the sample
domain.

In which case, it’s not a filter you want to use for the original
sampling.