# All Questions

7 views

### Beginner question: extracting features for image classification?

I'm a Python programmer, but a beginner to image processing :) Apologies if this isn't a suitable question for the forum, happy to rewrite or move. I want to create a supervised classifier to ...
10 views

### FIR filter compesation

I am currently passing a QAM modulated symbols through an FIR filter generated using fir1 function in MATLAB. It is a first order low pass filter and it is causing a rotated effect in my received ...
7 views

### Calculating Delta MFCC, correct formula?

I have seen different formulations of how to calculate delta mfccs. In general, I want to be consistent in such a way that if have other features to look at other than mfccs, the way I would ...
17 views

### Multiple parallel IIR bandpass filters with different centre frequencies combined into one filter for optimisation… possible?

Before I begin, I have read these already: IIR filter parallelization Concept of combining multiple FIR Filters into 1 FIR filter I am processing audio using Csound in a high performance real time ...
25 views

### block code error control with d >= c+u+1; c: #(correctible errors), d: code distance

This is about error control coding formula $$d \ge c+u+1$$ of a block code, with $c$ being the number of correctable errors, $u$ being the number of uncorrectable errors, and $d$ beinh the ...
46 views

### Time scaling in DFT?

Let $x[n]$ be a real signal whose length $N$ is even. Let $y[n]=x[2n]+jx[2n+1]$ a signal whose length is $M=\frac{N}{2}$. $X[k]$ for $k=0,...,N-1$ and $Y[k]$ for $k=0,...,M-1$ are the respective ...
14 views

### Question about vanishing moments in wavelet tranforms

I am reading the book Noise reduction by wavelet thresholding by Maarten Jansen. About vanishing moments, it reads To create a really sparse representation, we try to make coefficients that ...
25 views

### Analysis of a LTI system using DFT

Consider an LTI system $$H(z)=1-\frac{1}{2}z^{-1}+\frac{3}{4}z^{-2}$$ Let $x[n]=(\frac{1}{3})^n\cdot u[n]$ be the input signal. It is desired to determine the output for $n=0,1...,N_a$. To ...
25 views

### How to match a thumbnail to an area in the original image?

Suppose that you have a thumbnail and the original image from which it was generated. You need to match the thumbnail to an area in the original image that represents the original selection from which ...
34 views

### Find Natural Frequency $\omega_n$

You are testing a new device to determine its characteristics. You find the magnitude of its frequency response shows a peak at 500 Hz, and the measured overshoot of the step response is 40% of the ...
5 views

### How can I use a trained model to generate related images?

Suppose I have a data set of a large number of related images and I extract HOG features and train it using SVM Classifier or KNN Classifier. How can I use this model to generate a new image which is ...
7 views

### Repeater based pathing

I'm having trouble finding information on the topic I'm interested in, and maybe my problem is just how I'm wording things. So, let's say I have a repeater-based communication system, where one node ...
7 views

### Input/output for buck-boost converter controller implemented with FPGA

I'm not sure if this question is appropriate for DSP as I'm new to StackExchange, but I think it could be related. I am trying to implement a voltage controller for a buck-boost converter using FPGA. ...
23 views

### How to think about beamforming when there's no “space” between receivers?

I'm trying to wrap my head around how does "beamforming" work when there's no physical "space" between receivers. My background knowledge: I've always thought about beamforming as a sort of spacial ...
17 views

### Theory on distortion algorithms? [on hold]

Anyone know references for distortion algorithms (incl. saturation)? Particularly looking for something that characterizes them based on their sound as well as mathematics.
32 views

### What are the spike removal techniques in matlab without using filters

output from wavelet filter using daubechies 4 wavelet. Using wavelet filter this is the output obtained. The problem is elimination of the spikes at 0.023,0.043,0.063 and so on. Please note: no ...
13 views

### What is the difference between photon shot noise and salt and pepper noise?

I am currently working on an application which deals with the restoration of fluorescent beads examined using widefield microscopy. There are two major sources of noises that are being encountered in ...
30 views

### Gaussian wavelet generation of a given frequency

How can I generate a Gaussian wavelet (time domain) with a given central frequency. I mean, if I take the Fourier Transform then its spectrum should be around that given central frequency. For ...
30 views

### IQ imbalance amplitude

I have to fix the amplitude of measured IQ receiver data. According to my information about the data, I can estimate that one signal needs to be corrected to the other in amplitude. The phase ...
122 views

### Sampling Theorem: How to know the value between two samples of a Signal

According to Sampling theorem, in order to reconstruct a signal we need to sample it at the rate => twice the highest frequency component of that signal. (provided signal is band limited). Let's say, ...
19 views

### Matlab Adaptive Filters

In the audio domain, I am currently attempting to use Matlab to distil: 1) 'signal' from noise+signal 2) 'noise' from noise+signal using two adaptive filters --> two results. I get the first ...
15 views

36 views

### Calculus on sound signals?

I was playing with the idea of performing integration on a sound signal, since I've never heard of where it'd be used. Is it used somewhere? Here's something: ...
12 views

### Can I create a transformation matrix from rotation/translation vectors?

I'm trying to deskew an image that contains an element of known size. Here's a test image: I can use aruco::estimatePoseBoard which returns rotation and ...
10 views

### Image rotation - bilinear interpolation method

I am trying to rotate an image but I am getting unsuccessful results. I realise I can just use rotate functions in packages but I am trying to do this in a particular way so I can understand what is ...
12 views

### Relationship between symbol rate and carrier frequency

What is the exact relationship between symbol rate and the carrier frequency the symbol is modulated upon? And why do we specify the frequency of the carrier as its center frequency?
19 views

### Transform matrix creation in compressed sensing

In Compressed sensing ECG reconstruction I would like to use bi orthogonal wavelet basis as transform/sparsifying domain. I found out that ' wfilters ' command in matlab will give 4 type of filters, ...
11 views

### Filtering data on a known signal

I have data that is affected by temperature. How can I filter out the temperature signal considering I have temperature data collected?
15 views

### difference between wavelet filters

Some may think this question is little primarily,I just want to know the differences between different wavelet filters like decomposition high pass,low pass,reconstruction high pass,low pass ...
29 views

### Initial conditions for the LTI systems described as a difference equations

Why do we need the initial conditions to be zero for the LTI systems described as a difference equations? First question is why do we need it for linearity? I can't think of any example of the non ...
27 views

### What's the IDFT of this sequence?

Let $x[n]=0$ for $n<0$ and $n>63$. If $X[k]$ is its 64-point DFT and $X[32]=1$ while $X[k]$ is $0$ for any other value of $k$, what sequence is $x[n]$? I used the definition of IDFT and I got ...
19 views

### How to calculate the step response and transfer function

The output system is: $x(t)$ -->(S)--> $y(t) = \int_{-\infty}^{t}x(\tau) d\tau$ I am still not sure whether my work is correct, please some one advise me. I know that a step response is the ...
28 views

### Why is it better to sample white noise in frequency domain here?

We have a channel $c(t)$ that we want to sample. It can be expressed as $c(t)= g\ast x(t)$ where $x(t)$ is white complex Gaussian noise and $g(t)$ is a function that we know the PSD of, let's call it ...
5 views

### OpenCV: CascadeClassifier_CUDA [on hold]

I'm trying to use the CascadeClassifier_CUDA type in OpenCV, but I have problems with it. The compiler says that it is not a member of cv::cuda and I don't know why, I'm getting crazy... Here's my ...