Timeline for How can I interpolate between two FFTs?
Current License: CC BY-SA 3.0
17 events
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| May 17, 2017 at 9:14 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Apr 17, 2017 at 8:53 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Mar 18, 2017 at 14:21 | history | tweeted | twitter.com/StackSignals/status/843105170108141569 | ||
| Mar 18, 2017 at 8:31 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Feb 16, 2017 at 6:31 | answer | added | Dan Boschen | timeline score: 1 | |
| Feb 15, 2017 at 23:15 | comment | added | hotpaw2 | The other bins also need to be warped in equivalent proportion to how the nearest moved peak is being warped. Some stretching may need to be done so that bins between peaks stay between peaks after warping if they are warped by different ratios. Add Sinc interpolation for all the bins that end up being warped to a fractional bin spacing. Phase vocoder analysis and adjustment is also likely needed. | |
| Feb 15, 2017 at 22:56 | answer | added | Maximilian Matthé | timeline score: 0 | |
| Feb 15, 2017 at 22:21 | comment | added | JodiTheTigger | That was one path I was considering going down. However what do I do with all the frequencies next to the peaks? do I ignore them? Do I interpolate them somehow as well? | |
| Feb 15, 2017 at 21:59 | comment | added | Maximilian Matthé | Well, I think the matching between the peaks of A and B is the main issue here. It could be done by associating the peaks based on their sorted frequencies. However, first the peaks need to be detected. What should happen, if one FFT has more peaks than others? Once you have associations between input frequencies and output frequencies, you can create a mapping that performs a e.g. piece-wise linear mapping between input and output frequencies. | |
| Feb 15, 2017 at 21:50 | comment | added | JodiTheTigger | Yes, I suppose I do, I want to "sweep" the peak in a at frequency fa, to the peak at b at frequency fb. Or interpolate between these two peaks, where phase, magnitude and frequency are interpolated. However this is just a simplified explination. My actual FFT has multiple peaks, and it might not be obvious which peak in A maps to which peak in B (but that's starting to get out of scope of the question). | |
| Feb 15, 2017 at 21:40 | review | Close votes | |||
| Feb 19, 2017 at 1:12 | |||||
| Feb 15, 2017 at 21:33 | comment | added | endolith | You want to sweep the frequency peaks to new frequencies over time? You'll need to do some kind of peak picking first to identify what counts as a "peak", then synthesize whatever sweep shape you want. I imagine it will sound weird. The A and B spectra always have the same number of frequencies? And it's obvious how one maps to the other? Or are you saying that you want to "expand" all frequencies simultaneously? Like a spectral stretching? | |
| Feb 15, 2017 at 21:24 | comment | added | JodiTheTigger | Done. Hopefully this has clear up your questions. | |
| Feb 15, 2017 at 21:23 | history | edited | JodiTheTigger | CC BY-SA 3.0 | Clarified question, labelled graph axis, documented use case. |
| Feb 15, 2017 at 20:45 | comment | added | Maximilian Matthé | Welcome to dsp.se! Your question is definitely interesting, but I think a bit more context is needed. Pleased edit your question to include the following: What is your application? What do you mean by interpolate between two FFT? What do your figures show (In particular, please add axis labels)? What is input to the algorithm you look for and what should the output then look like? (I think this is what you want to show with your ASCII-art) | |
| Feb 15, 2017 at 20:43 | review | First posts | |||
| Feb 15, 2017 at 21:05 | |||||
| Feb 15, 2017 at 20:33 | history | asked | JodiTheTigger | CC BY-SA 3.0 |