0
votes
1answer
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 ...
0
votes
0answers
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 ...
0
votes
1answer
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 ...
0
votes
0answers
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 ...
0
votes
1answer
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 ...
0
votes
1answer
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 ...
0
votes
1answer
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 ...
0
votes
1answer
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 ...
1
vote
0answers
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 ...
0
votes
1answer
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 ...
0
votes
0answers
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 ...
0
votes
0answers
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 ...
0
votes
0answers
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. ...
0
votes
0answers
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 ...
0
votes
0answers
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.
0
votes
2answers
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 ...
0
votes
1answer
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 ...
0
votes
1answer
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 ...
1
vote
1answer
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 ...
3
votes
4answers
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, ...
0
votes
1answer
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 ...
1
vote
1answer
15 views

Unit step function present in convolution result

We are currently learning about convolution in my signals and systems class, and one of our textbook problems is to compute the convolution of $x(t) = e^{-\alpha t} u(t)$ and $y(t) = e^{-\beta t} ...
0
votes
0answers
6 views

LTI system: solving for the time at which a system state reaches a given value

Suppose I have the following Linear Time Invariant (LTI) system: \begin{equation} \dot{x}(t) = Ax(t) + Bu(t) \end{equation} where $x(t)=\begin{bmatrix}x_1(t) & x_2(t) &\ldots ...
1
vote
1answer
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: ...
0
votes
0answers
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 ...
0
votes
0answers
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 ...
0
votes
0answers
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?
1
vote
1answer
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, ...
0
votes
1answer
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?
0
votes
1answer
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 ...
0
votes
1answer
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 ...
0
votes
0answers
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 ...
0
votes
0answers
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 ...
1
vote
0answers
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 ...
0
votes
0answers
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 ...
0
votes
1answer
32 views

Hilbert Transform from FFT?

For a school project, I'm working on a software-defined radio transmitter intended for the HF amateur radio bands. I'm planning to support SSB transmission with the formula $$f(t) = m(t) \cos(2\pi ...
1
vote
1answer
26 views

DFT of a cosine/sine wave?

I'm seeing everywhere that the DFT of a sinusoid (i.e. a sine that has been windowed with a rectangular window) are just two deltas. What I don't understand is why the DFT is not the convolution of ...
0
votes
0answers
12 views

Improve coverage of BackgroundSubtractorMOG2 and findContours

I'm trying to track players on a soccer field, using a fixed camera. The picture below shows the results of BackgroundSubtractorMOG2, the second picture below the results of findContours on the ...
0
votes
0answers
9 views

Specifications (N) FIR Low Pass Resamplig, Hamming Window

I'm learning about DSP and I've doubts. The resampling process can be do it with only one filter. $L$: Increment Sample Rate Integer $M$: Decrement Sample Rate Integer $f_S$: Frequency Sampling ...
0
votes
0answers
6 views

Valid non stationary non parametric white noise tests for non strick stationary time series

I could not find a question where testing for white noise for non strick stationary non parametric time series is adressed. Traditionally testing for white noise is done via multiple tests for the ...
0
votes
0answers
24 views

Applying Filter to Complex Data

I have data being streamed in the time domain, I would like to use a transfer function for a low pass filter in order to filter the data. I use DFT to get the data to the frequency domain, in the form ...
0
votes
0answers
9 views

extraction of image using tikhonov regularization in matlab [on hold]

i have created inverse problem y=Hx where H has toeplitz structure of dimension 2976X2976 and y contains information about image(some raw data for a each pixel). i implement this using Orthogonal ...
1
vote
2answers
40 views

How to subtract one signal from another?

I am capturing some body internal signals. I am using 2 identical mics. One captures the in body signal and one open air. I want to remove/delete/subtract the open air signal (noise for me) from the ...
0
votes
0answers
8 views

How can I improvise matlab code from GLCM to CLCM(Color Level Co occurrence Matrix) for feature extraction in texture analysis?

Currently I am doing my project on SKIN DISEASE DIAGNOSIS USING TEXTURE ANALYSIS in IMAGE PROCESSING domain.In this project,the histopathological image of diseased skin image is given as input and the ...
0
votes
0answers
19 views

joining word samples into a sentence

I have a bunch of single-word samples for use in a command-and-control voice interface. These words are played in a certain sequence to compose sentences. It's fast (even on low-powered device), cheap ...
0
votes
0answers
24 views

Development board with 4-pos jack and USB

Perhaps I do not know how to research this correctly--I mostly looked at large sites like digikey and mouser--but I can't seem to find a small development board that has: one (ideally two) 3.5 mm ...
0
votes
0answers
11 views

Laser Pointer Detection

In my project I want to develop a robust Algorithm to detect laser pointer in the projected screen and my algorithm want to find it's X,Y co-ordinate.Can anyone suggest some algorithms to find laser ...
0
votes
1answer
51 views

Daubechies wavelet transform

i have N samples obtained by sampling a signal with lot of frequency contents. How will i apply daubechies wavelet transform to obtain the frequency and its location? i need to write a program which ...
3
votes
1answer
58 views

Downsampling and Then Upsampling

Given this system: I need to show the $\mathcal Z$-transform of $y[n]$ as a function of the $\mathcal Z$-transform of $x[n]$. Now I know that for downsampling alone: $$Y(z) = ...
1
vote
1answer
85 views

What is the benefit of FFT when we're already sampling at an acceptable rate?

As I'm learning about DSP I can understand the process of taking a continuous signal into a discrete signal. I understand an oscillator producing different types of signals, including a periodic ...

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