Signal Processing Stack Exchange
Signal Processing Stack Exchange

Most Popular

more tags
1500 questions
13
votes
2 answers

What is spectral entropy?

Can anyone explain what spectral entropy is? Does noise with a restricted bandwidth have the same spectral entropy as white noise?
user15987
13
votes
3 answers

Documentation about filters in general

I already posted this question on StackOverflow. I got a suggestion to go for a better answer here. To make the question more concise I'm interested in an introduction to digital filters, any resource is good. But first I will be satisfied if…
Iulian Şerbănoiu
  • 233
  • 1
  • 6
13
votes
1 answer

What is an AMDF?

The wikipedia page for Average Magnitude Difference Function/Formula (AMDF) appears to be empty. What is an AMDF? What are AMDF's properties? What are AMDF's strengths and weaknesses, as compared to other pitch estimation methods such as…
hotpaw2
  • 35,346
  • 9
  • 47
  • 90
13
votes
3 answers

How to Average Complex Responses (and Justification)?

I am developing software that calculates the response of a system by comparing the FFT of input and output signals. The input and output signals are divided into windows and, for each window, the signals are median-subtracted and multiplied by a…
andrew cooke
  • 233
  • 2
  • 8
13
votes
2 answers

Necessary image processing operations before template matching

Well, this may show I didn't take image processing class. I have this template to match an object in images. But real object in images, for example, does not look like that but the second image. What operations do I need to take for the images like…
Tae-Sung Shin
  • 1,229
  • 1
  • 9
  • 19
13
votes
4 answers

Efficiently calculating autocorrelation using FFTs

I'm trying to calculate an autocorrelation on a platform where the only accelerated primitive I have available is the (I)FFT. I'm having a problem though. I prototyped it in MATLAB. I am, however, slightly confused. I assumed that it works simply as…
Goz
  • 475
  • 1
  • 9
  • 21
13
votes
3 answers

How do I compare 2 audio files, returning a percentage of difference

Is there a way to compare 2 audio files, whereby a percentage of difference will be returned? I am using C# VS08, .net framework 3.5. Edited: difference in the sound (like for eg. Audio 1: "HELP", Audio 2:"HELP ME PLEASE", it will return the…
Daniel
13
votes
2 answers

Converting a pitch bend (MIDI) value to a "normal" pitch value

I am trying an offline LPC analysis and synthesis using the rt_lpc (real-time LPC) implementation as given here. There are some functions within the program that can be used for an offline LPC analysis and synthesis program. The rt_lpc code is…
Sriram
  • 578
  • 1
  • 6
  • 12
13
votes
3 answers

Image processing coding

I was wondering which is the best language for image processing? I know MATLAB has a good library and user community for it. I havent checked it out, its there for python as well. What is the most efficient language for this?
phoenix
  • 131
  • 3
13
votes
2 answers

What Does an Adaptive Filter Do?

I studied a bit about adaptive filter on internet and found that its a special filter which keep on updating its filter value as soon as it proceeds. It finds out the difference between input and output and using the error function and previous…
Prashant Singh
  • 457
  • 2
  • 5
  • 11
13
votes
5 answers

Discrete-time Fourier transform

I am a junior high school student who has a general fascination for electronics, programming, and the like. Recently, I have been learning about signal processing. Unfortunately, I haven't done much calculus yet (forgive me), so I am a little fuzzy…
ElectroNerd
  • 131
  • 1
  • 5
13
votes
2 answers

The current state of the art in audio signal interpolation

Three questions: What are all the metrics one can use to measure audio interpolation quality, objectively? (but also in terms of psychoacoustics if possible) By those metrics, what is the current state of the art in audio interpolation? Suppose I…
Bent Rasmussen
  • 233
  • 2
  • 7
13
votes
7 answers

Obtain a signal's peak value if it's frequency lies between two bin centers

Please suppose the following: The frequency of a signal's fundamental has been estimated using FFT and some frequency estimation methods and is lying between two bin centers The sampling frequency is fixed Computational effort is not an…
lR8n6i
  • 321
  • 5
  • 19
13
votes
2 answers

Deriving the Fourier transform of cosine and sine

In this answer, Jim Clay writes: ... use the fact that $\mathcal F\{\cos(x)\} = \frac{\delta(w - 1) + \delta(w + 1)}{2}$ ... The expression above is not too different from $\mathcal F\{{\cos(2\pi…
pyler
  • 347
  • 1
  • 2
  • 8
13
votes
2 answers

Detecting drum bpm in a noisy .wav file

I am looking for algorithm(s) to solve the following problem: Given a noisy .wav sound capture (some wind + friction noise on the microphone), how to detect the BPM of a soft drum beat? I have attempted googling the subject, but the results are…
Alex K
  • 275
  • 1
  • 5
1 2 3
…
99 100