0
votes
0answers
6 views

How to apply a Butterworth filter to data of varying sample rate?

I am trying to apply a Butterworth bandpass filter to accelerometer data of my smartphone. However, the accelerometer samples I receive do not come at regular intervals. Sample frequency varies ...
0
votes
1answer
19 views

Matlab: is a highpass filter what I want, to obtain my required spectrogram? How do I design/apply this? (pic included)

The axes are wrong in the spectrogram. I have an audio wav file, and I know the sampling rate. this is read into the audioData variable. The audio is 1 channel. selected window length I believe (can't ...
0
votes
0answers
8 views

Efficiently compute bases functions of the signal

Let there be 4 1D signals such that \begin{cases} x(t)=4\sin(10\pi t) \\ y(t)=8\cos(20\pi t) \\ z(t)=16\sin(30\pi t) \\ m(t)=x(t) +y(t)-z(t) \end{cases} Is there a way to compute ...
0
votes
1answer
9 views

SFBC Alamouti Scheme LTE

That a 2$\times$1 Alamouti SFBC is referred to as a rate 1 code, two symbols are sent over two adjacent subcarriers. Reference: Fundamentals of LTE Book. This question is regarding this SFBC encoder ...
0
votes
0answers
19 views

Fixing drift in a recursive fixed point filter

I'm implementing a 80-72-64-48 multi pass moving average filter for a embedded system in C and in fixed point. The implementation is a circular buffer where i'm keeping a running sum and calculating ...
0
votes
0answers
15 views

How to calculate Dot Pitch for a device?

Okay I am trying to figure out how to calculate the dot pitch for a monitor. For example a 14inch monitor with a display area of 9.875inch and a height of 7.125inch and a diagonal 12.25inch with a ...
-1
votes
2answers
22 views

Filtering Random Signal

My question is easy one actually. First, I generate a random signal using randn() function of MATLAB like this: Then, I design a FIR filter of order 200 of ...
0
votes
1answer
12 views

differences between 2D and 3D Medical Images

i have two questions: 1)what is the difference between 2D and 3D medical images? 2)assume i have a 2D image and for example it contains 1000 ROIs. each ROI is a matrix and we can convert it to a ...
2
votes
1answer
134 views

Is it only me or matlab's periodogram's function is confusing?

I am really confused with matlab's periodogram. First of all, it says in the documentation that its unit is "dB per unit frequency". What does that really mean? I just don't quite get it. Second of ...
0
votes
0answers
11 views

how can we apply dirichlet power spectrum and dirichlet transform in signal processing? and how Dirichlet work in signal? [on hold]

Currently, I'm doing research on vibration signal. I've extracted some features just by using simple statistical features. I directly extract the features from time and frequency domain. Now, my ...
0
votes
1answer
23 views

Can we decompose a correlated random variable into correlated plus uncorrelated?

Assume a random sequence $ Y_k = X_k \cdot H_k + W_k $ where $X_k$ is a deterministic quantity, $H_k$ is a correlated random sequence, $W_k$ is Additive White Gaussian random sequence. Can we ...
0
votes
0answers
17 views

Distance Transformation in image processing

What is the exact purpose of distance transformation in image restoration. Is it a way to restore or only a step towards restoration of a blur image?
0
votes
1answer
35 views

FIR design using firpm (Parks-Mclellan)

Can you please help me with some ideas on how to implement an FIR filter in Matlab using Parks-Mclellan algorithm? My specifications are the passband cut-off frequency, the transition bandwidth. The ...
0
votes
1answer
25 views

ISI Nyquist criterion and spectral efficiency

While reading Bernard Sklar's Digital Communications book I've got confused with ISI Nyquist criterion (not Nyquist rate criterion). There is stated (Sklar, 3.3 section) for symbol rate $R_s$ minimum ...
0
votes
1answer
69 views

Fourier Transform of a Distcrete Sequence Periodic?

Why do we say that the Fourier transform of a discrete sequence is continuous, for example here Fourier transform converts every discrete sequence in continuous spectrumMy first question is for the ...
0
votes
0answers
25 views

the significance of these two successive bumps

Suppose there is a sin curve with amplitude A, which is I=ASin(t)* . If we detect two small bumps near two successive peaks of the ...
1
vote
0answers
19 views

cause of adaptive threshold poor result

I try to run text cleaning process based on the camera captured image. By using OpenCV adaptive threshold method with parameter ...
1
vote
1answer
30 views

What is the cause of slow roll off of windowed filters

Exactly why using the of windowing function, such as Hamming or Blackman, causes a slower transition to stop band? Everywhere it is mentioned just as an obvious fact that this happens but I haven't ...
0
votes
0answers
6 views

ZCR and Energy features for VOT problem?

Can I use Zero Crossing Rate (ZCR) and Energy features for a VOT detection problem? Is it the same as in Voiced/Unvoiced classification problem? or are there any differences? Thank you in advance ...
0
votes
0answers
5 views

use of recurrence quantification analysis for deterministic signal identification and classification

The recurrence quantification analysis (RQA) is a method of nonlinear data analysis which quantifies the number and duration of recurrences of a dynamical system presented by its state space ...
0
votes
1answer
39 views

How does a matched filter know about input signal beforehand?

I know that a matched filter at time t0 is just the input signal reversed in time about that time. But how does the filter know about input signal. Received signal is transmitted signal plus the noise ...
0
votes
0answers
26 views

Filter signal1 from evolving frequency response of signal2

I'm a composer (of music) starting out with signal processing. I'm also reasonably proficient in C at this point. I'm not even sure if what I'm trying to do is possible, because I can't yet find an ...
0
votes
0answers
23 views

State Space representation

I'm trying to change this filter transfer function to state space representation $ y_t=\frac{1+b_1 z^{-1}}{1+a_1 z^{-1} +a_2 z^{-2}}u_t $ I tried writing it as time series $ y_t+a_1 ...
0
votes
0answers
12 views

optical character recognition [on hold]

I am working on a school project about optical character recognition. My major is electrical engineering so using matlab is preferable but some people say that working with openCV is easier since it ...
0
votes
0answers
9 views

segmentation using fuzzy c means [on hold]

how to calculate segmentation accuracy,how we extract the information from an MINC file regarding the class of a pixel to which it belongs,so that we can compare it with our segmented result.
0
votes
0answers
23 views

How to detect nuclei in cell

I want to detect the nuclei in this picture. Anyone know the Matlab code? Because I use watershed it's not performing well.
0
votes
2answers
22 views

Pulse Shaping in Digital communication

I am new here. I hope I can get help. I want to ask a question regarding digital communication. Does anyone know what are pulse shaping used for? Are they used for ISI mitigation or for something ...
0
votes
1answer
24 views

Do FIR filter have any application in control theory?

I know about IIR filter as discrete pendent to transfer functions in the Laplace domain. So it is actually quite simple to convert the function of the control system and finally receive the discrete ...
0
votes
1answer
9 views

Is there any reason that cross correlation would perform well or poorly on sparse binary arrays?

I am using matlab xcorr to correlate simulated photon count data that has some Gaussian random noise set on top of it and it is working fine when the average value ...
2
votes
2answers
41 views

OFDM modulator in LTE

My understanding of what an OFDM modulator does, is that it takes a parallel sequence of QAM symbols of size M, pads it with zeroes corresponding to the zero subcarriers, then passes them through an ...
0
votes
1answer
22 views

How to change the angle unit labels on polar plot in MATLAB?

I hope this is not off-topic. I'm wondering is there anyway to change the default angle unit label in MATLAB polar plot. The default angle label is from 0 to 360, at 30 increment. It goes like ...
0
votes
0answers
15 views

frequency domain image analysis for recognition purposes

There are many areas like, gait analysis, where we recognize persons by analyzing their silhouettes taken while they are at different stages of their walking where analysis also carried on in ...
0
votes
1answer
38 views

Where is the “time and frequency” in a Discrete Wavelet Transform?

The DWT is motivated by the ability to see signal in time and frequency at the same time, if I understood that correctly. I am using the following Matlab commands for some signal x: ...
0
votes
2answers
33 views

Decibels conversion into amplitude ratio

I want to convert db into amplitude ratio. I did some research but I only found online convertor, and I don't understand what's on Wikipedia very well... Here is a little of backstory : I am a ...
0
votes
2answers
33 views

Median filter algorithm in opencv

I was wondering about the implementation of the Median Filter in opencv because I am suffering form its slowness. So, I intend to implement another one on my own but first I want to make sure about ...
2
votes
2answers
146 views
+50

Fourier Decomposition

Hello everyone have a look at this video of Fourier Decomposition of an image(otherwise you can also refer the image which shows few plots of different extracted waves from an image) . We also know ...
0
votes
0answers
7 views

Multilayer perceptron

i am doing a project on Keyword spotting.here i have to segment the word spotted.but i am stuck here in doing the coding for segmentation.i m going to use MLP(Multilayer Perceptron) for ...
0
votes
1answer
23 views

Lane detection and tracking using B-snake?

I am truly sorry if my question sounds little bit stupid, but I am getting stuck at this part for a long time. I am currently working for my final year project of lane detection for curved road using ...
0
votes
0answers
15 views

Optical Flow Problems

I was wondering if any of you guys could help me with the next 3 problems. They're about estimating the lamda on the Optical Flow equation $E = E_s + λE_c$, for different situations that try to ...
0
votes
2answers
60 views

Inverse z transform - help

How can I find inverse z transform of $$X(z)=\frac{5}{(z-2)^{2}}$$ ? It is known that x[n] is causal. EDIT: Here is what I have done. Since signal x(n) is causal, convergence of z transform of that ...
2
votes
0answers
50 views

Analyzing accelerometer data: appropriate use of rotation matrices?

I'm working on a project in which a rod is attached at one end to a rotating shaft. So, as the shaft rotates from 0 to ~100 degrees back-and-forth (in the xy plane), so does the rod. I mounted a ...
1
vote
1answer
61 views

Root Locus for a system

I know this subject tends more to control theory but I am certain its part of the global knowledge basis for engineers, thus I believe I can find the answer here. I'm trying to draw Root Locus for ...
-3
votes
0answers
31 views

Discrete-time Fourier transform and Discrete Fourier transform [on hold]

$x(n)$ has a DTFT of $x(e^{j \omega})$and $g(n)$ $g(n)=x(n)+x(n+N/2)$. Find the $N/2$ DFT of $g(n)$ in terms of $x(e^{j \omega})$.
-3
votes
0answers
40 views

DSP homework help [on hold]

can you please guide me throw this Using a single 4-point DFT, compute the DFT of the sequences $g[n] = [1, 0, -1, 0]$ and $h[n] = [0, 2 ,0 , -2]$, $0 ≤ n ≤ 3$.
-1
votes
0answers
30 views

solving a 12-point DFT [on hold]

Some values for the 12-point DFT, X12(k), for a length-4 real sequence x[n] are given in the table below ...
1
vote
2answers
112 views

Finding the Harmonics contained in an Image?

I am beginer in image processing. Any signal whether it is 1D,2D or any multidimensional signal can be represented using combination of number of sine and cosine wavesforms (harmonics). Similerly any ...
0
votes
1answer
33 views

Spectral analysis of a time series with missing data points

I use a PC to record time series of some physical property. The problem is that, for some reason, I did not record the time series as a whole, rather I record first segment, then second, third, etc. ...
1
vote
0answers
48 views

How do I interpolate between bins on an FFT in python?

I have four frequency peaks, which I have after applying FFT. Now I want to know precise values of these frequency peaks. there are different interpolation methods. How can I use this method of ...
0
votes
0answers
28 views

Why is MRI more expensive than CT?

I am not asking how MRI scans are different from CT scans, but rather why they are more expensive. I know that CT scans take longer for starters, and am wondering whether this is essentially the only ...
0
votes
0answers
16 views

Finger Detection on various backgrounds

I tried tracking down the finger placed in the frame. Constraints: Algorithm works in live streaming of USB Camera, so there will be a lot of background changes. Algorithms tried: Tried ...

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