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1500 questions
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1 answer

Creating a spectrogram

I've been trying to work out the logic for this task, and plan to use the KissFFT source package to perform the fast fourier transform. Please let me know if this looks about right: Allocate an FFT structure, ie.…
raynebc
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Programming a Vocoder

I'm want to program my own vocoder synthesizer like "Songify" but I can't find a simple of vocoder algorithm. Maybe you can explain or tell where to look for information on how vocoder works.
Rytis Alekna
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How to remove certain background from image?

This was the image obtained after Gabor filtering... Is there some way of removing the lines inside the image except the bright white rounded defect. Did try another orientation of gabor filter go the following result: After thresholding :Which is…
vini
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Apply a Gabor filter to an input image

I tried to apply a Gabor filter with a specific scale (according to my values of lambda and sigma, so it is (7x7) and for 4 orientations (0, $\frac{\pi}{4}$, $\frac{\pi}{2}$ and $\frac{3\pi}{4}$) to a input gray scale image. In my code, three steps…
Liszt
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4 answers

For an LTI system, why does the Fourier transform of the impulse response give the frequency response?

I know that for a given system, the Fourier transform of its impulse response gives its frequency response. I want to find where this property comes from, but haven't been able to find if it's a definition or if there's a mathematical proof…
Florian Castellane
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Intuitive interpretation of Laplace transform

So I am getting to grasps with Fourier transforms. Intuitively now I definately understand what it does and will soon follow some classes on the mathematics (so the actual subject). But then I go on reading about the laplace transform and there I…
Leo
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How Hessian feature detector works?

I know about Harris corner detector, and I understand the basic idea of its second moment matrix, $$M = \left[ \begin{array}{cc} I_x^2 & I_xI_y \\ I_xI_y & I_y^2 \end{array} \right]$$, edges and other unstable points can be removed via $M$. But…
avocado
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1/n octave smoothing

Given a frequency response obtained with FFT, I would like to apply a 1/n octave smoothing. What filter should I be using and how? Maybe someone could point to a good reference (a paper or book on the subject).
Psirus
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How do I go about detecting whistles, pops and other sounds in live audio input?

I've read many questions on SO, and frankly, each one of them is not describing any particular way to go about it. Some say "do FFT" and some say "zero crossing" etc. But I've only gone as far as understanding that the digital audio input consists…
bad_keypoints
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Practical wideband digital beamforming for large arrays in radar applications

I do understand the mathematics behind digital beamforming but I am not sure how such systems are practically implemented. For example, in a typical wideband FMCW radar operating in S-band, the (baseband) pulse bandwidth can be as large as 500MHz.…
user4673
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What is the difference between Lumped and Distributed systems?

What are the salient differences between Lumped and Distributed systems? In what contexts are distributed systems the appropriate model and in what are lumped systems the appropriate model? Also, Lumped systems are said to be described by ordinary…
Gowtham
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Detecting a filled glass object

I've been sent here from this question in stackoverflow, please excuse me if the question comes too specific and it's not in the manners in here:) The task is to find a glass with specific liquid in it. Let me show you the pictures and then describe…
user1916182
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DFT-like transform using triangle waves instead of sin waves

We know that DFT (discrete Fourier transform) breaks down a signal into multiple frequencies of sine waves. Does there exist a transform that does the same thing, but for triangle waves? For my purposes, im only talking about 1-d signals (like…
hassan789
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Roberts Edge Detector how to use?

I am trying to use Roberts edge detection to process an image. Do I just apply both of the masks to the image and perform convolution as normal? Could someone give me the breakdown of how to use this edge detection method, as I am trying to program…
adamjmarkham
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What is the name of a low-pass filter that tracks rate of change?

When applying a low-pass filter to a constantly changing signal, there will be a lag between the actual value and the filtered value. For example, if f(x) = x, the regular low-pass filter output will always be less than f(x). I remember coming…
jpa
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