It also makes no sense to me, and I also have a DSP degree. Of course moving averages (aka box blurs) filter out higher frequencies more than middle frequencies.
Homework assignment: make a bode plot of the convolution filters [1 1 1] vs [1 2 1].
Which one turns +1, -1, +1, -1, .. into all zeroes?
You ought to know this because the fourier transform of [1 0 1] is a cosine of amplitude 2 on the complex unit circle e^(i*omega), which means the DC quefrency needs to be 2 to get the zeroes to end up at nyquist.
The frequency response H(z) (= H(e^i*omega)) of [1 1 1] on the other hand will have its minimum somewhere in the middle.
Also here's a post that will teach you how to sight read the frequency response of symmetric FIR filters off the coefficients:
https://acko.net/blog/stable-fiddusion/
The degree to which people defend poor scholarship and writing on HN these days is frankly pathetic.
There is nothing about that intro that is offensive. Reading comprehension ought to tell you that "pun intended" is a joke to make the bitter pill that OP wrote garbage easier to swallow.
Sesse__|18 days ago
unconed|17 days ago
Which one turns +1, -1, +1, -1, .. into all zeroes?
You ought to know this because the fourier transform of [1 0 1] is a cosine of amplitude 2 on the complex unit circle e^(i*omega), which means the DC quefrency needs to be 2 to get the zeroes to end up at nyquist.
The frequency response H(z) (= H(e^i*omega)) of [1 1 1] on the other hand will have its minimum somewhere in the middle.
Also here's a post that will teach you how to sight read the frequency response of symmetric FIR filters off the coefficients: https://acko.net/blog/stable-fiddusion/
unconed|17 days ago
There is nothing about that intro that is offensive. Reading comprehension ought to tell you that "pun intended" is a joke to make the bitter pill that OP wrote garbage easier to swallow.