# Tag Info

Accepted

### Why would one use a Hann or Bartlett window?

In reviewing fred harris' Figures of Merit for various windows (Table 1 in this link) the Hamming is compared to the Hanning (Hann) at various values of $\alpha$ and from that it is clear that the ...
• 43.4k
Accepted

### Proof that the rectangular window has the best resolution

Wikipedia has a very nice article on window functions https://en.wikipedia.org/wiki/Window_function The basic trade-offs in windows is main lobe width vs side lobe height and overall attenuation. The ...
• 37.8k

### FFT with asymmetric windowing?

I'll use the shorthand window for "window function". With audio, any processing that creates something akin to pre-ringing or pre-echo will sound sloshy like a low bit-rate mp3. This happens when ...
• 12.9k
Accepted

### Is spectral leakage due to windowing 'different' for the DTFT and DFT?

The concept of spectral leakage is not dependent on the context, and it's the same thing for the DTFT as it is for the DFT. It's probably helpful to remember that the DFT of a finite length sequence ...
• 84.3k
Accepted

### Why do we use window in time domain rather than do FFT modify the spectrum and than inverse FFT

Windowing reduces spectral leakage. Say you start out with a $\sin(y) = \cos(\omega_0 t)$. The period is obviously $2 \pi/ \omega_0$. But if nobody told you that the period is $2 \pi/ \omega$ ...
• 106
Accepted

### Why are there so many windowing functions?

Aside from reduction of spectral leakage, there is a one major trade-off to be made when choosing a window function. Below you can see a figure with various parameters. Two of them are most important: ...
• 10.8k
Accepted

### Fourier transform artifacts

The cross pattern is typically a border effect, due to the periodicity induced by the standard implementation and hypotheses behind the Fast Fourier transform, when the image lacks periodicity from ...
• 31.1k
Accepted

### Why is each window/frame overlapping?

Why is each window/frame overlapping? Windowing is a means to stationarize signals. Inside a small enough window, you can expect that the properties of the signal chunk do not vary too fast. And you ...
• 31.1k
Accepted

### python scipy fft on numpy hanning window smears peaks

Is this meant to happen? Yes, that is absolutely a well known effect of using any window function. Taking a look through the Wikipedia article on window functions, we find that the rectangular window ...
• 1,026
Accepted

### Effect of windowing on noise

UPDATE: My previous response did not answer the OP's question. The following addresses the question directly: Bottom line: Prior to windowing in time, each sample in frequency is an IID Gaussian ...
• 43.4k