Signal Processing newsletter

Top new questions this week:

How does Delta-Sigma Modulation convert a 1-bit signal to higher resolution signal?

I've looked at various resources about Delta-Sigma modulators, and I find them fascinating. However, I'm confused on a particular point and and am looking for an explanation. In my understanding, …

sampling

asked by Kenneide 4 votes answered by chirlu 1 vote

How can I perform object tracking using noisy images?

The problem Take 50+ of Lena images, add gaussian noise to them to the point that you couldn't say it is Lena. I insist, gaussian noise, not gaussian blurring. Now imagine a cropping window randomly …

image-processing video-processing

asked by Gael 3 votes

Removing unwanted peaks from signal

I have a signal which looks something like: The 12 main round peaks is what I'd like to keep. However, the peak detection algorithm I apply is picking up the in-between noisy peaks. Any strategies …

noise signal-analysis signal-detection peak-detection

asked by by0 3 votes answered by pichenettes 3 votes

Fitting fixed number of complex exponentials to complex signal

I have a complex data series, and I would like to fit a fixed number (in this case, two) of complex exponentials of the form $Ae^{jBn}$, where A, B are complex. Not interested in the phase (i.e. arg …

discrete-signals frequency estimation

asked by James 3 votes answered by geometrikal 4 votes

Image gradient computation by convolution matrix

Prewitt operator is a common operator to compute image gradient in edge detection, and I knew that to apply this Prewitt operator to an image is just to convolve them together, say, the image is …

image-processing convolution

asked by loganecolss 3 votes answered by geometrikal 4 votes

Eigenvalues and eigenvectors of a 3D image Laplacian

I need to compute the eigenvalues and eigenvectors of a 3D image Laplacian. All the information and examples I have read are for 2D images. The specific questions are: How can I obtain a 2D matrix …

image-processing 3d

asked by Federico 2 votes answered by Dr.D. 0 votes

SNR calculation in audio reconstruction and what is an acceptable value

I have the original signal, a .wav file and by blind source separation, i have reconstructed the signal. How can I calculate the SNR in this case? or is it good to use any other performance …

audio source-separation

asked by afnitha 2 votes answered by pichenettes 2 votes

Greatest hits from previous weeks:

How to estimate a transfer function from a magnitude-only frequency response?

Given an arbitrary frequency response, what signal processing methods might exist that could guess, estimate or determine a transfer function (pole and zero constellation) which gives a "reasonably …

transfer-function frequency-response zeros

asked by hotpaw2 8 votes answered by Jason R 9 votes

Why should I zero-pad a signal before taking the Fourier transform?

In an answer to a previous question, it was stated that one should zero-pad the input signals (add zeros to the end so that at least half of the wave is "blank") What's the reason for this?

fft

asked by Jonas 19 votes answered by hotpaw2 23 votes

Can you answer these?

Harmonics on periodic functions

Ok I need to understand how some harmonic calculations work to apply some transforms. If I have a periodic functiion f(x). And I have the values of that function for several values of x (say x goes …

transform

asked by Atirag 2 votes

Does an asymmetric Bernoulli matrix satisfy the RIP?

Define an $n\times N$ sensing matrix $A$ by $A_{ij} = 0$ with probability $p$, and $A_{ij} = 1/\sqrt{n}$ with probability $1-p$. Does $A$ satisfy the restricted isometry property? For reference, the …

compressive-sensing

asked by olivia 2 votes