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I'm looking for two signals embedded in very noisy data. I know they are close to periodic and integral with the run, but are rather close (30s and 21s during a 210s measurement), and our sampling rate is low (1.25s). We have multiple observations to work with per sample.
I am wondering how I might deal with the proble... |
I am trying to understand the logic behind unsharp filter in matlab. If I type:
image = imread('nameoffile');
filter = fspecial('unsharp', 0.5);
resultImage = imfilter(image, filter);
resultImage is sharper than image. I opened fspecial.m file and saw that unsharp filter is created as:
h = [0 0 0;0 1 0;0 0 0] - fspec... |
I sent a square wave signal (red) through a IIR filter (butterworth in this case), to make it more "realistic". Then there's a slight group delay in my output signal (blue). Is there a way to find out what the group delay is? I only need the total group delay, not spectrum of group delay. I need the number so I can shi... |
I'm trying to detect the presence of a sinusoid in 1/f noise conditions using the STFT and the DWT with Haar wavelets. I find this interesting phenomenon that I'm not able to explain (see plot at 1)
My sampling rate is 1200 Hz and the graphs show the one sided response (0-600 Hz). I am using 2 scales for the Wavelet Tr... |
I am trying to understand where does the convolution fit in Discrete Fourier Transform. I know that convolution is producing a third signal from two other signals. I also know that DFT transforms one signal from time to frequency domain.
So, what is the relationship between the two (if any)?
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i got that system $x_n \to x_n-x_{n-1}$, so $h_n=[.....,0,1,-1,0,...]$, with $h_0=1$ and $h_1=-1$, so the transfer function given by:
$$\sum_{i=-\infty}^{\infty} h_ne^{-jwn} = h_0e^{-jw(0)}+h_1e^{-jw(1)}=1-e^{-jw}$$. How to knwo the type of filter, if it is HPF, LPF, etc.
I appreciate your help.
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I know that while taking pictures from a camera, noise may appear in the image.
It is often described as Gaussian, but what about the other noises, when do they occur in real world?
Please help!
|
I have an image that I am trying to process:
I want two seamingly contradictory effects:
I want to remove "holes" inside "the blob". That is I want all pixels inside the blob to be solid red.
I want to move the boundary of the blob inwards.
From what I gather the morphological operation dilatation would do 1. and er... |
i got a system with transfer function given by:
$$H(\omega)=1-e^{-j\omega}$$
I already plot it, and that seems to be a periodic function with $H(0)=0$, $H(\pi)=2$, , is that enough to show that this is a FIR bandpass filter. thank you very much
|
What is the role of complex exponential $ e^{jθ} $ in Fourier Transform? Is it different in the continuous and in discrete time domain?
|
Is it possible to generate the z-domain transfer function from a pole-zero plot diagram?
|
If I have, for example a 16-QAM signal, and the constellation points are (3,3),(3,1),(1,3),(1,1),...(-3,-3).
Now I have a simulated in coming signal with arbitrary power, how can I normalize the signal to this constellation so I can make correct decisions?
The first thing I could think of is to calculate the average po... |
Using the Fourier transformation I can translate a signal from the time-domain to the frequency-domain. If I divide the frequency axis into intervals, how can I calculate the audios signals energy for each of these intervals?
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I have a sensor that reports its readings with a time stamp and a value. However, it does not generate readings at a fixed rate.
I find the variable rate data difficult to deal with. Most filters expect a fixed sample rate. Drawing graphs is easier with a fixed sample rate as well.
Is there an algorithm to resample fro... |
I want to learn how to design structures that could model difference equations. I don't know how we call this things but i can show a picture:
For example i want to understand the procedure that using addition, multiplication and delay operators like the above i can describe equations like: $ y(k)=1/2(x(k)+x(k-1)) $
D... |
While reading a description on FFT from this book, I found the following statement:
...diluting the time domain with zeros corresponds to a duplication of
the frequency spectrum.
How can I prove this intuitively or otherwise? I have read some properties of Fourier Transform, such as a circular shift in time domain... |
I'm working on an OFDM-QPSK based system and I'm having some trouble to match the BER of my system with the theoretical curve. My OFDM implementation fills all the subcarriers and have t_symbol s duration and t_cp cyclic prefix duration. I'm trying this to validate my system implementation before go on with my system d... |
Is there a verb for removing the mean or DC component of a signal? I am trying to name a flag for doing just that.
"Normalize" can mean many things, so I don't think that would be a good choice.
|
I found an approximation of a 5x5 2D convolution kernel like this :
Here, the sum of the elements is zero and this one was used for Laplacian of Gaussian!
Another one here :
This one has all positive and the sum is not zero and is being used for smoothing.
Could anyone please tell me what is with the sum being zero i... |
I am given 256 samples at a sampling rate of 48k and am asked to find the frequency of dominate tones and the amplitude of the largest tone. The data looks like this when plotted:
I assume I must use a FFT transform to do this. I've tried this in matlab:
Fs = 48000;
x = dataSet; % 256 samples data set
xdft = fft(x);
... |
I am trying to write an image processing program to recognize bubbles in oil.
It has been suggested I try computing the convolution of the image and an image of a typical bubble.
i.e. : ifft(fft(a).fft(b)) will have high peaks near bubbles.
where:
ifft : inverse fourier transform
fft : fourier transform
a : the imag... |
I read many sources about kalman filter, yet no about the other approach to filtering, where canonical parametrization instead of moments parametrization is used.
So I would like to learn on examples how to use this filter with information matrix and information vector (not mean and covariance from KF).
Can anyone he... |
In an old paper "A New Approach to Geometry of Range Difference Location", there is a mathematical derivation that does not include any mention of the relationship to the underlying problem. In the problem, there are 3 receivers (at $(x_1, y_1)$, $(x_2, y_2)$, and $(x_3, y_3)$) and a transmitter at unknown position $(x... |
I am learning DFT and I am not sure I understand it correctly. I am just going to write out the process of DFT and I am asking you to tell me if I am thinking the right way.
Suppose we have a signal on which we run DFT to get the frequencies incorporated in the signal. We use a window of size N samples and calculate D... |
I showed the question about flipping the impulse response to some math teachers and electrical engineers at an university. They read Dilip's answer and thought that it was hard to understand what Dilip meant and it was simply not true...
Could someone confirm that it really isn't true what Dilip Sarwate wrote. And expl... |
From what I have read about signal (de)modulation I understand that multiplying two sine waves, both with the same frequency, gives a two frequency component sine wave. One at DC and one at $2\omega$. Using a low pass filter will let us remove the $2\omega$ component. Now DC amplitude is proportional to the phase diffe... |
We have several audio tracks, all of which are different versions of the same track under one type of distortion: the speed of the track is increased by a constant factor K (hence frequences are multiplied by K, timesteps are divided by K), K is relatively small (0.8< K < 1.2).
I want to know the best way to get a good... |
I am implementing a method known as trace transform for image analysis. The algorithm extracts a lot of features of an image (in my case features pertained to texture) using a set of transforms on the values of the pixels. Here is a paper describing the algorithm: (PDF link).
The algorithm finally constructs a "triple ... |
I'm trying to do a CT Fourier Transform of these two signals
$$x_1(t)=e^{−a(t−1)} \cdot u(t−1)$$
and
$$x_2(t)=e^{−a(t−1)} \cdot u(t)$$
Where $a$ is any real number, and $u(t)$ is the unit step function and that is multiplication, not convolution.
Picture of my work and answers here.
The answers listed should not conta... |
I'm analysing several measurements taken with a SR830 lockin amplifier.
These measurements look similar to this one.
Since I'm interrested in the derivative of the signal I took the numerical difference. What I found was this.
One can clearly see two bands in the signal. I'm no expert, but I'm guessing it might be rel... |
I have a two data set files data1 and data2 each containing 5000 points having 3 columns representing x,y(coordinate (centroid)),angular movement(theta) resepectively for two robot movements obtained by numerical programming and solution of a circuit representing robot equations.I need to simulate a graph for coverage ... |
Maybe a stupid question, but if there is a time-domain representation of audio signal, and also frequency-domain, so is there any other domain that signal can be represented in?
|
I want to fuse objects coming from several sensors, with different (sometimes overlapping!) fields of view. Having object lists, how can I determine whether some objects observed by different sensors are in fact the same object? Only then I can truly write an algorithm to predict future state of such an object.
In othe... |
I need to filter the image raster below with the following mask:
0 1
-1 0
and the Image Raster:
0 0 0 0 0 1
0 0 0 0 1 1
0 0 0 1 1 1
0 0 1 1 1 1
1 1 1 1 1 1
My results are:
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
-1 0 0 0 0
In what direction does this mask detect intensity change? What does the sign of the output signal me... |
I have a bunch of simulated time series, for which I can compute the power spectrum. Generally, the simulated power spectrum can be sketched as follows:
I now aim to calculate the features of the theoretical power spectrum. The theoretical power spectrum can be represented by:
$$ S_{th}=\frac{4\left(L/U_{hub}\right)}{... |
I want to use GMM for image classification.
So, I have extracted SIFT features from each image in the corpus.
Then, I apply EM algorithm to learn GMM parameters (I have coded it in matlab).
I get very low Recognition rates for unseen images when I test the model on larger number of classes (>=4).
Who can explain this ... |
I have got a question concerning the definition of the frequency vector for an fft operation.
Generally, I work with a frequency vector, f, with power of 2 elements (2048, 4096, 8192, ...).
Given a certain simulation analysis time, time (e.g. 600s), I should define f as follows:
% Frequency defition
t = 0:dt:(time-dt);... |
This is MR Modality Link
MR Modality
In this file where i find the LV Cavity in above link file. Also how to draw Tumor Marker from over it
|
The matlab "ellip" function can be used to design the unquantised coefficient set.
From matlab website:
$ [b,a]=ellip(n,Rp,Rs,Wp) , $
n: order of filter
Wp: normalized passband edge frequency
Rp: ripple in passband (db)
Rs: db down from he peak value in the passband
If i have an 8th order IIR filter with the foll... |
Plotting the FFT of a signal with Matlab e.g. by the code:
y_fft = abs(fft(y));
f = fs*(0:length(y)-1)/length(y);
plot(f,y_fft);
where y is the discrete signal and 'fs' is sample rate. creates a plot where the curve can be mirrored in the middle of the x-axis e.g.
Why can the FFT always be mirrored in the middle of t... |
I'm reading an IEEE standard and it says that the first channel needs to be 50dB below the highest power in a 6 MHz operating channel in 100 KHz bandwidth. It was mentioned several times that the power spectrum measurement needs to be done over a 100 KHz bandwidth. Isn't it sufficient to just say that the power of the ... |
Suppose we have create an IIR filter with matlab function "ellip", and then we want to quantize the coefficients using:
\begin{align*}
bq=Quantize('round',b,2^8); \cr
aq=Quantize('round',a,2^8);
\end{align*}
I have read that there are 4 major types of rounding:
truncate
round
convergent rounding
round-to-zero
What i... |
I am doing R&D over the MR Segmentation to draw marker over the Heart MR Dicom Images. My Question is that how I can draw a such marker over the dicom image that show in attach/link image. that Region of Interesr ROI read from the tag or its part of Pixel Processing.
|
1 2 1 1 2 1
2 4 2 (A) (1/16) * 2 4 2 (B)
1 2 1 1 2 1
Both matrices are the same except that the matrix B is multiplied by the sum of its elements.
When convolved with an image, they give nearly the same blurred image.
What is the exact dif... |
I would like to ask what could be the easiest way to detect the presence and beginning (no more, no less) of under-damped harmonic signal in a collect of ultrasound data. I have some acquired data which is presented in 2-D image form, where vertical axis are related with time. Under-damped harmonic signal, which I need... |
I have a GMSK modulator in MATLAB and wish to generate AWGN with a specific SNR, and I'm having some issues figuring out just how.
I have found this step-by-step process to generate zero-mean Gaussian noise with a specified power spectral density W0:
Form Gaussian distributed random variable: w = randn(1,N)
Map top ze... |
How can I obtain the wavelet filter coefficients ( i.e. lowpass decomposition filter, highpass decomposition filter, lowpass reconstruction filter, highpass reconstruction filter) for the Morlet wavelet?
For convenience: the wavelet curve follows the equation $$\pi^{1/4} \exp(jwx) \exp(-0.5x... |
I have values (plotted below) of expected RSSI values over time that I would like to compare with my measured RSSI values. What I was looking for was a way to quantify it so I can change parameters and be able to compare/contrast different approaches.
It is a hard problem in my mind because I don't know how to compare... |
I have some programming experiences but am really new to these kind of algorithms. I can find a few source code about implementing HHT, and most of them are written with MATLAB. What I am trying to do:
Apply HHT algorithm in detection of image splicing. I want to find object edges in images.
Implement this with C/C++... |
I'm currently reading a paper and I can't seem to make sense of a certain part. A link to the paper: removed
The part I don't quite get is on page 286 (after the part where they explain their filters). It starts with the sentence "Two common methods can be used ...". They explain how they calculate the interbeat interv... |
I am a little confused as to how to compute the nyquist criterion for a sensor array that is not linear, and/or non-uniform. For the linear, uniformly spaced case, the spatial nyquist is delimited by finding the half-wavelength that fits between the space of two adjacent sensors. Thus, if the distance between two senso... |
I don't if I am posting my question in the correct place. I have tried hard to solved it but I am unsuccessful.
I have an structuring element shown below:
1 1 1
1 1 1
1 1 1
My image is:
11 11
11 11
11 11
11 11
1111111
11 11
11 11
11 11
11 11
11 11
I have to apply erosion using the above image and s... |
I want to eliminate spurious peaks of Hilbert transform for finding glottal closure in the linear prediction (LP) residual. I have the following 4 steps:
Down-sample.
Hilbert Transform.
Identify Peaks in Hilbert Transform.
Consider this hypothesis that time gap between two successive glottal closure instance is not li... |
I am trying to get the position data from an IMU 6 Degrees of Freedom (MPU-6150) board using an Arduino Uno. I am trying Jeff Rowberg’s example MPU6050_DMP6.ino that may be found here.
This is the first time I am working with an IMU. I have no idea whether it's possible to get the position data using the using quaterni... |
i am working on simulation of an article "A Real-time ECG Data Compression Algorithm for a Digital Holter System". This algorithm has five steps "Difference=> ECG Signal=>Classification=> DCT=> Window Filter => Huffman" . it described window filter as "In order to implement a high compression ratio, the DCT window size... |
The cyan plot is a spectrum of 50 Hz, and the magenta one is a 50.1 Hz sine wave (having amplitude 0.7). Both are sampled at 1024 samples/s. I performed a 1024 point FFT to get this spectrum.
Why is only the 50Hz spectrum a single value? Why does the 50.1 Hz sine consist of other frequencies apart from 50.1 Hz; where... |
I would like to create an algorithm that, given an iddata, estimates different armax models with different na, nb, nc, nk, and finally show the compare plot.
I know how to use the armax estimation function, but how can I store the model in a variable in a such that I can compare them later?
|
I'm testing an OFDM system implemented in fixed point. The data format is Q11. My system work's fine but I need to test it under some channel for evaluation of the design before field testing. The system will be tested on Rician fading channel but for now I'm working on AWGN testing first. I asked a similar question he... |
I was looking for a more efficient way of finding the magnitude and phase of a signal at a certain frequency without performing an FFT because it produces more information than I need and I came across this comment on the Matlab message board:
http://www.mathworks.com/matlabcentral/newsreader/view_original/250421.
If I... |
After so much search on google i find out few things hope so that correct for detecting Left ventricles of hearth and draw the Region of Interest(ROI) on MR Modality .
Can you give me please more detiails idea about "Morphology Algorithm" for tumore detection in heart of LV
|
If i add the two tones then the result if two peaks are added together will be greater then the the sample max (2^15).
For the life of me I couldn't think of the right words to google. Think i have google block.
|
I am collecting a 15Hz sine wave at 1500Hz. Therefore, every 100 points of data collected should contain a single complete sine wave. If I sample for 10 seconds, I will have 15000 points of data. If I perform an FFT on this data I will have very high frequency resolution. However, If I wanted to divide these 15000 po... |
It could seem an easy question and without any doubts it is but I'm trying to calculate the variance of white Gaussian noise without any result.
The power spectral density (PSD) of additive white Gaussian noise (AWGN) is $\frac{N_0}{2}$ while the autocorrelation is $\frac{N_0}{2}\delta(\tau)$, so variance is infinite?
|
How to detection of the boundary of the left ventricle from MR images, the crucial step is to determine the region of interest (ROI) or the center point (CP) of the left ventricle.
I just want to show this marker over the Left ventricle of heart of MR Dicom Image
|
I was supposed to find state space representation and its matrices of this system:
and I have no idea, how to do this. We were told not to transfer the system to time domain, but I can only do state space representation from time domain schemas.
When I tried to solve this, I got matrices
$$A = \left( \begin{array}{cc... |
I experiment with the coefficient quantization in an IIR filter. I change some values like the passband ripple and also how many bits i want for the quantization method. In the first picture i have 1db passband ripple , 'round'and 7-bits as the quantization method:
In the second picture i have 1.3db as the passband ri... |
I want to implement an IIR filter. The filter is going to implement by cascading second order sections. Below there are 3 pictures that implement this filter using:
Denominator - Numerator using Tapped Delay Line Structure 2:
Numerator -Denominator using Time Delay and Accumulate Structure 3:
Denominator - Nominator ... |
I want to detect the regions of voice in a song. Currently, I am using the fact that the vocals in the song are recorded as center panned. So, I am removing all center panned audio from the song. However, this removes other instruments such as bass also. So, it sometimes gives false indication of voice being present.
I... |
I have noticed that the spectrogram for a audio signal is often calculated in different ways when the result from the DFT is transformed into real numbers; some tend to compute $|k|$ or $|k|^2$ while others use the formula $Re(k)^2 + Im(k)^2\ \ $ for each DFT bin $k$. What is the theoretic difference between these and ... |
The optimal binary detector for asymmetric, equiprobable PAM pulse normally have structure as shown below,
But I cannot understand what is the multiplier and the integrator using for.
Why the detector need to care the signal difference and multiply with the received signal?
Why can't I directly put the received sig... |
suppose that we have a wave which has some peaks in some indexes like 2,12,25,... and otherwise zero.
I want to extract the time lag or lags between peaks of a signal. could anyone help me ?
|
Does anyone knows can i find a FFT of 1536 length input. Its a specification given in 3gpp Lte and we need a transform of 1536 input size which is neither a power of any number i would say. I just need a theoretical idea.
|
Long story short, I have a sinusoidal wave with DC offset going in with a given frequency of say 100 Hz and $\phi = 0$ (which I'm guessing is really $\pi/2$ since it is a sine wave not cosine). I get an output of the same frequency and, using FFT, I would like to find the phase between these two. What I did is I found ... |
@Jim Clay: No if the filter varies slowly, then the clicks go away. So I guess the filter needs to vary slowly to avoid audible clicking sounds.
I created a test in matlab where I'm comparing time-domain filtering with frequency-domain filtering. The two operations produce the same output, but I get clicks in the audio... |
I am trying to understand and visualize the concept of a covariance matrix. Suppose I have a matrix:
$A = \begin{pmatrix} 2 & 3 & 4\\ 5 & 5 & 6 \end{pmatrix}$
how do I calculate its covariance matrix, and what is its practical meaning?
(All I was able to understand by now is that on the diagonal of the covariance matr... |
I have a noisy signal with jumps to high value and back to normal for limited time bins (40 for example) which I want to filter to have a smooth signal with no jumps. Here is the graph, the blue one.
I tried moving average filter (n=20), the green one. Also tried window based (kaiser) LPF with cut-off freq=0.01 (I ch... |
I have already asked this question 2 times, but still i am confused because this is not available anywhere on the internet and explained properly. I found some information in this document and i am going to apply their method , but confused to understand. here is the document Altera Application Note 480: 1536-Point FFT... |
I have been asking around if the way I was extracting phase shift (lag) was correct, and I ran into some trouble.
So in general, given 2 arrays of data of the same length, representing:
the input sinusoid and
the response, also a sinusoid.
So not knowing the functions that produced the input (but knowing the frequen... |
Hi guys, I've been reading some papers on - how to remove ghosting artefacts from the Fourier Slice theorem applied to a 3D discrete image volume. The papers mention that in order to remove ghosting artefacts "employ a better(and typically wider) interpolation filter".
Currently, in Matlab I fft a 3D image space volume... |
I heard that the padding with zeros is mainly for efficiency and speed, other than that, is there a downside to use fft(signal) instead of fft(signal, N) where N is a power of 2 assuming signal length is not a power of 2.
Thank you
|
I have to implement a second order filter in DF1 or DF2. I should avoid housekeeping operations by suitable addressing strategies.
I don't understand what "housekeeping operations" means. Anyone could help me or propose a source i can find more information?
EDIT :
I use DF2 for the second-order filter:
As pichenettes... |
I am trying to convert from a floating point number to a Q-notation signed 16-bit fixed point number (e.g. Q15). How can this be done in C or Java? I searched online but could not find any available code.
|
I'm learning DSP slowly and trying to wrap my head around some terminology:
Question 1: Suppose I have the following filter difference equation:
$$y[n] = 2 x[n] + 4 x[n-2] + 6 x[n-3] + 8 x[n-4]$$
There are 4 coefficients on the right-hand side. Are the "number of taps" also 4? Is the "filter order" also 4?
Question 2... |
I have 2 sin waves:
Fs = 1500;
N = 100;
t = (0:N-1)'/Fs;
sinwave = sin(2*pi*15*t);
sinwaveshifted = sin(2*pi*15*t + 1.3);
If I get the magnitude at 15Hz using an fft (need to use an FFT that is a power of 2 for reasons beyond my control):
fftsin = fft(sinwave,128);
fftsinshift = fft(sinwaveshifted,128);
% 2 correspo... |
What is the difference between an impulse and a step response diagram?
|
Does anyone have any experience designing wideband IIR Hilbert transform filters with audio applications in mind? I am using the filter for single side band modulation audio effects discussed in this paper :-http://www.mikrocontroller.net/attachment/33905/Audio_Hilbert_WAR19.pdf.
I tried to implement the design techniq... |
I have been working on a simple low pass filter for < 100 Hz metering in my application. But so far, I am struggling with the theory behind it all. It's cool that I got it working, but I'd really enjoy it if I knew how/why it is working.
I found the following code:
void getLPCoefficientsButterworth2Pole(const int sampl... |
I am trying to bandpass filter a signal using a butterworth filter, but I am getting the following result (click to enlarge):
The original signal is the blue and the filtered one is the green.
Why does the first part of the filtered signal (from 0 to 50) is changing so much from the original? Can you help me understa... |
I have two plots, each having frequency as x-axis and Gain as y-axis. By taking one data set as a reference I have to calculate similarity between them.
The graphs have same values on the x-axis and have same range on the x axis
Can 2D Correlation or Co-variance can do a decent job ? or
should I opt for Fréchet distan... |
I have a discrete signal. I want to do sinusoidal regression to estimate the parameters such as amplitude, phase, frequency, etc.
It is important to note I only have the signal values and have no time when these values were recorded.
How could I possibly do the sine regression?
Thanks.
|
INPUT
x[0] = (0.00 + j 0.00)
x[1] = (1.00 + j 0.00)
x[2] = (2.00 + j 0.00)
x[3] = (3.00 + j 0.00)
x[4] = (4.00 + j 0.00)
x[5] = (5.00 + j 0.00)
x[6] = (6.00 + j 0.00)
x[7] = (7.00 + j 0.00)
x[8] = (8.00 + j 0.00)
x[9] = (9.00 + j 0.00)
x[10] = (0.00 + j 0.00)
x[11] = (0.00 + j 0.00)
x[12] = (0.00 + j 0.00)
x[13] = (0.0... |
I have an image like the one above, and what I need to find are the red circled areas. They are caused by how the nerve layer is in the eye, and I have no idea what method to use to extract them. (I am looking for a brighter background from the nerve layer)
I have found all the blood vessels, so I can ignore those are... |
The periodic square wave,
$$x(t) = 1, |t| < T_1 \\
x(t) = 0, T_1 < |t| < T/2$$
What I wonder is ..
(1) If $T_1$ is constant and $T \to \infty$, is x(t) a constant function?
(2) If $T_1$ is constant and $T \to 0$, is this non-sense?
(3) If $T$ is constant and $T_1 \to 2/T$, is x(t) a constant function?
(4) If $T$ is con... |
I have been trying to implement an algorithm for successfully counting cars in an image. I have tried implementing A Method for Vehicle Count in the Presence of
Multiple-Vehicle Occlusions in Traffic Images
It estimates the background from a set of various images. I have looked into various other techniques for this pu... |
I need to transform this function:
$$
x(t) = 4\sin(20\pi t ) - 5\cos(24\pi t ) + 3\sin(120\pi t )
$$
into a sequence $x(n)$ given that the sampling frequency should be 50 Hz. So that means the sampling interval $T = \frac{1}{50} = 0.02\ s\ $. So would the sequence be:
$$
x[n] = 4\sin(20\pi0.02n ) - 5\cos(24\pi 0.02n )... |
I am working on the implementation of a location recognition pipeline as detailed in the section 5.4 of the paper Leveraging 3D City Models for Rotation Invariant Place-of-Interest Recognition:
Vocabulary tree + Inverted File System + SIFT detector/descriptors (discarding features not lying on a building using geometri... |
I have a bunch of short axis MRI images of the heart(Left Ventricle), in dicom format.
I want to do a Automatic segmentation of various structures in these images.
Does anyone know of a program I could use? (a C# would be fine also)
I basically just need a program which allows me to select a couple of
points on the ima... |
I am currently trying to count cars using OpenCV 2.4.4 with a HOG descriptor. Because a model for car detection is not available in OpenCV, I am creating my own model using SVMLight and a dataset of cars from the INRIA car dataset here (positive and negative samples).
I created the model using the positive and negative... |
What is the definition of Generalized Cross Correlation?
I need it for estimating the delay (time offset) between two audio signals. The time offset between the two signals might be as large as 500ms.
|
I have seen that in OFDM, the sampling rate is much lesser than twice the bandwidth of signal. why is it so? How is sampling rate calculated in OFDM? Does it depend on the modulation type used inside like QAM or BPSK. Does it relate to FFT length by any chance.
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