-1
votes
0answers
10 views

matlab coding to combine FIR and IIR filters [on hold]

Design filter using IIR highpass filter with cutoff frequency, fc1 = 20 Hz and FIR bandpass filter with cutoff frequency fc2 = 10 Hz and fc3 = 15 Hz. What is your designed ...
0
votes
0answers
3 views

How to use Matlab's 512 element lookup table array in OpenCV?

I am designing morphological operations in OpenCV. I am trying to mimic the functions remove and bridge in Matlab's bwmorph. To do this I referred to the function definition of bwmorph.m, there I ...
-2
votes
0answers
13 views

tooth isolation code [on hold]

I am currently working with dental images and I need to separate each tooth from the image. I find difficult to do it so.
0
votes
2answers
23 views

Generate 3D image from multiple 2D images

If we're to capture an image of a body using four (4) WebCam with a 16 megapixel (1 in the front, 1 in the back and 2 sides(left and right)). Is it possible to make a 3D out of it using image ...
0
votes
0answers
9 views

MATLAB : $\tt imwarp$ allots too much space [on hold]

I'm finding the projective transform from some set of correspondences. I'm using this as input to imwarp along with an image. My computer freezes at times. I have ...
0
votes
0answers
13 views

Loop bandwidth for symbol timing recovery

I am trying to design the Symbol timing recovery (STR) block of DVBS Receiver. How should I chose the loop bandwidth and damping ratio for determining the loop filter coefficients $k_1$ and $k_2$? ...
-2
votes
1answer
37 views

What is a filter bank?

I have three Gabor filters. I am applying them to an image serially. Is this the correct concept of a Filter Bank? What if I want to apply the filter in parallel? I am using Accord.NET framework. ...
0
votes
0answers
8 views

What are various types of Gabor Filters?

Gabor Filter has 4 types of kernels: Real Imaginary Complex Magnitude Squared Magnitude What do they actually mean? NB. Please, supply me any resource for further study.
4
votes
5answers
72 views

Why do digital filters work?

So I just started reading on FIR and IIR filters and am amazed by how "simple" the theory seems, so far. But what confuses me is, why does filtering work by creating a weighted sum of previous ...
0
votes
0answers
18 views

Upsampling with FIR filter causing discontinuity at start of new buffer

I have implemented an oversampling algorithm for an audio signal in C++ which is producing a distortion of the signal at the start of a buffer. The algorithm is wrapped in a class with methods for up ...
1
vote
1answer
40 views

Amplitude transfer function

Given a LTI-system $$y[n]=x[n]-2x[n-1]+y[n-1]- \frac{8}{9}y[n-2]$$ The transfer function $H(z)$ is: $$H(z) = \frac{1-2z^{-1}}{1-z^{-1}+ \frac{8}{9} z^{-2}} $$ How do I calculate the amplitude ...
3
votes
1answer
19 views

Measuring the open loop transfer function in closed loop: what's the better approach?

Considering the closed loop system; $C$,$G$, and $H$ all linear and stable transfer functions, If I chose to excite $\bf r$ and measure $\bf e$, I get the Sensitivity Function, $S$ ...
0
votes
2answers
13 views

Periodicity of transfer function of FIR filter proof (Parks and Burrus, Digital Filter Design)

In Digital Filter Design by Parks and Burrus, p. 19. The transfer function of an FIR filter is given by the $\mathcal Z$-transform of $h(n)$ as: $$H(z)=\sum_{n=0}^{N-1}h(n)z^{-n}$$ (where $h$ is ...
0
votes
0answers
5 views

Limitations of inter-sample cross-correlation in time-shift detection

I wish to find the time shift value of a (noisy) signal to the highest degree of precision that is possible. The amount of time shift is not an integer amount of samples. First, calculating the ...
1
vote
0answers
24 views

Basic tools for digital filter design?

What tools to use for practicing elementary filter design? Is Matlab all there is? Do I need some specific tool boxes? What functions do I need? I'm starting from the ground up in digital filter ...
0
votes
1answer
32 views

Spectral plot shows more notes than there really should be

I was experimenting with sound analysis lately and from what I see when I plot spectral data of an audio file is that apart from notes that were actually picked there are some other notes with quite ...
0
votes
0answers
20 views

what is the disadvantages of the following [on hold]

Wavelet Stft Dft Frequency response Mann and morison technique Mux A/D converter Also what is ment by aliasing problem and watch dog property Recursive and non recursive
0
votes
1answer
17 views

Soft question: Seeking compressive sensing imaging demo in MATLAB

I am looking to experiment in MATLAB with image restoration/reconstruction using compressed sensing. I am relatively new to compressive sensing, and was inspired by the following Wired article to ...
0
votes
0answers
26 views

Artifacts in sub-sample delay

There are at least two ways of achieving sub-sample delay. One is to simply over-sample the signal and then delay it by the wanted sub-sample amount. The over-sampling is equivalent to creating new ...
-2
votes
0answers
21 views

How to identify a similar voice audio? [on hold]

I want to implement an application where given an audio containing a speech as query,it returns the most similar audio that was already submitted by an other user. Here two audio are similar if they ...
1
vote
1answer
36 views

Difference between $\tt rand()$ and $\tt randn()$ in MATLAB

rand() is for "Uniformly distributed pseudorandom numbers" I generate two rand arrays, and then use the cross-correlation ...
0
votes
1answer
26 views

How to derive the transmitted signal from a constellation diagram

Let us assume we have $16$ symbols to transmit. We can represent these $16$ symbols by $16$ unique signals and transmit. If at the receiver we can identify these $16$ signals correctly, we have ...
0
votes
0answers
14 views

Projector image subtraction

Imagine you have a projector and camera pointed at a wall, with people walking in front of the wall (between projector and wall). Is there a standard way to robustly obtain silhouettes of the people ...
1
vote
3answers
46 views

Where and how do an Image and a complex number meet?

I am trying to implement a Gabor Filter bank. Gabor Filter uses a complex function. How do the filters like Gabor Filter operate on an Image? Does a complex number represent an entire Image or only ...
1
vote
2answers
57 views

Method of reconstructing a band-limited signal from discrete samples

I understand current cell phones use digital communications. Given that this industry brings in billions of dollars each year, there is much incentive to get the best performance possible. So what ...
0
votes
0answers
18 views

Different results for different orders of estimating AR model using Yule-Walker equations

I'm trying to use MATLAB to estimate the AR parameters to the following filter: $$H(z) = \frac{1}{1-0.5z^{-1}+0.25z^{-2} -0.25z^{-4}}$$ As I can see, the process at the output of this filter depends ...
-2
votes
0answers
14 views

Exponential power delay/decay channel

If I want my channel gain to resemble an exponential power delay profile is it enough to define h= [1 0.66] if I have two channel taps (i.e memory length of ...
-1
votes
0answers
11 views

How to hide the number on the constellation points in matlab? [migrated]

This is how you plot a constellation: hMod = comm.RectangularQAMModulator('ModulationOrder',32, ... 'SymbolMapping','binary'); constellation(hMod) but how do ...
0
votes
1answer
19 views

Poster detection in OpenCV?

I'm really new in image processing, so please sorry I'm a newbie. I tried to use the squares.cpp for detecting posters (since they usually are rectangles) without using expensive feature detectors ...
0
votes
2answers
44 views

Why noise canceling headphones do not attenuate the signal itself?

Noise canceling headphones use a microphone to capture noise in order to cancel it. How is it guaranteed that the microphone will not record the actual signal and attenuate it?
0
votes
0answers
17 views

Hyperspectral vs Multispectral Imaging

I understand that the difference between the two are the number and width of the bands. Given a hyperspectral image, is it possible to 'convert' it to multispectral ? In this paper for example, the ...
1
vote
0answers
26 views

Time recovery - GNU Radio

I read about Time recovery (as an example, the Mueller&Muller algorithm); it is linked to when you should sample your signal. I am currently working on a project with GNU Radio and there is ...
1
vote
2answers
50 views

Conversion into the Q31 Format

I have a Setup, where I receive 24-bit ADC samples in the two's complement in 8-bit chunks. Usually I just "converted" them into a signed 32-bit integer like this: ...
5
votes
0answers
19 views

Why are some JPEG files of the same scene much larger than others? [on hold]

I'm using a Foscam FI8910W ip camera to view a static scene under constant lighting conditions. When I pull back a frame grab, it's about 35 KB in size. I can do this over and over and it's always ...
-3
votes
0answers
14 views

Why SEs (symbol error) are not same?

I simulated 16 QAM in MATLAB using binary and Gray coding. In both cases SE should be same even though bit error (BE) will be less in case of Gray coding. I wrote the following MATLAB program to ...
4
votes
1answer
49 views

Difference between a digital lock-in amplifier and a FFT when extracting phase of a signal?

I am trying to measure the relative phase of a sine wave fixed at a particular frequency in a noisy environment. My initial approach is to simply collect $N$ samples, take an FFT, and then just ...
0
votes
0answers
11 views

Why Auto-regressive model is considered closed loop while Moving-average model is considered open loop? [on hold]

In AR(2) I use the previous two readings to predict the present reading. then I use the present and the reading before to predict the future reading. This seems an open loop to me! It seems to me as a ...
0
votes
1answer
11 views

how to find nonzero numbers in Error? [on hold]

i have my orignial signal X and recovered signal X_re i want find nonzero number in my Error ...
0
votes
1answer
27 views

How to find PSD (Power spectral density) of spatial data

I have profiled a surface, measuring the height of peaks and troughs at 0.02mm intervals. I have 1501 data points, the below listed as an example: $$\begin{align} x &= 0\,\mu\text m & y ...
-2
votes
0answers
10 views

How to apply color change in any image with any Color? [on hold]

I want to change the color of a region of this image like this: to What is the algorithm behid this:
0
votes
0answers
11 views

How to take half window in wavelets signals and taking for different signals

I want to know how to take few cycles in a signal by half window technique. And how to do standard deviation,min,max points and how to use window analysis, taking different cycles and doing half ...
0
votes
2answers
46 views

How does BER performance depend on gray or natural binary?

I read that BER performance would be improved if Gray code is used in 16 QAM rather than natural binary coding. I think that it should not depend on the coding used. 16 QAM simply assigns to each of ...
0
votes
0answers
24 views

Combined low pass and notch filter design

I designed low pass filter with cut-off frequency $5\textrm{ Hz}$ and notch filter with notch frequency of $50\textrm{ Hz}$ and the corresponding MATLAB code is shown below. ...
-2
votes
0answers
14 views

Read an avi file and extract a frame from video in octave [on hold]

GNU octave 4.0.0 packages control 3.0.0 signal 1.3.2 I have switched from windows to Linux made to work with octave. I used to read the the video and extract the frame using "VideoReader" and ...
0
votes
0answers
21 views

FFT in different coordinate systems

Is there a transformation that will enable one to calculate the FFT in an arbitrary coordinate system? What I am interested is the following two cases: The space is Euclidean and infinitely ...
0
votes
0answers
31 views

What is the Center Frequency of Gabor Filter?

If the standard form of a Gabor function is as follows, $$ g_{\lambda, \theta,\varphi, \sigma,\gamma}(x, ...
0
votes
0answers
12 views

Image retrieval approach

I have a good understanding of 'normal' Machine Learning, I'm pretty good at Python and have decided to start a Raspberry Pi project, however my knowledge of Image Retrieval is limited. I'm trying to ...
-2
votes
0answers
15 views

steady state - calculate [on hold]

$$x[n]=10 \cos⁡(0.4nπ+45°)+20 \cos⁡(0.5nπ+30°)$$ That is a steady state input. I think that to solve and join them in one, we must apply this formula: $$cos⁡(x)+cos⁡(y)=2cos((x+y)/2)cos((x-y)/2)$$ ...
0
votes
1answer
34 views

How do I interpret the result of a Fourier Transform?

For example, I entered the following "equation" into Wolfram|Alpha: FourierTransform[Piecewise[{{sin[t],t > 0 and t < 2*pi}}, 0], t, \[Omega]] So as to ...
0
votes
2answers
15 views

How to calculate to structure tensor?

Structure Tensor is a matrix in form: $S=\begin{pmatrix} W \ast I_x^2 & W \ast (I_xI_y)\\ W \ast (I_xI_y) & W \ast I_y^2 \end{pmatrix}$ where $W$ is a smoothing kernel (e.g a Gaussian ...

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