MATLAB (MATrix LABoratory) is a numerical computing environment and a fourth-generation programming language. Use this tag with care.. see excerpt.
1
vote
0answers
50 views
voice with a random noise redction - MATLAB
I have this assignment that I can't figure how to solve.
I have a sound.wav human-voice file, and a matlab add-random-noise (monotonic)
Goal: remove the noise from the sound (and the sound from the ...
-1
votes
0answers
19 views
Produce a 4:2:2 sub sampled Y matrix, Cr matrix, Cb matrix for an image
I have write the matlab code below for to extract Y, Cb, Cr information from the picture:
...
-1
votes
4answers
54 views
Number of elements of an array
I want to found how many elements in an array is not equal to zero. I use this code:
y=sum(img_dct~=0);
z=sum(y);
Can i make this with a different way? Is there ...
0
votes
1answer
29 views
Plot the magnitude of coefficients against frequencies of DCT transform
When we perform DCT transform using matlab:
...
1
vote
1answer
41 views
Signal approximation using linear combination of functions
How I can approximate the signal $x(t)=0.001\,t^3 \exp(-0.1t)$ in the interval $[0,100]$ using a linear combination of the following functions:
$f_1(t)=A_1$
$f_2(t)=A_2\cos(0.05t)$
...
-3
votes
0answers
31 views
DSP MATLAB example question about notch filter!! [closed]
![this is the example question from the dsp using MAtlab edition 2, using the sources I have it was quite hard to answer it correctly. Needs you guys help!!][1]
[1]: ...
0
votes
3answers
61 views
similar tools for MATLAB ? [closed]
I have DSP in my academics , I am here to have a suggestion regarding the better alternative to MATLAB because of Its downloading size.
Thank you.
2
votes
1answer
99 views
Spectrum of a zero-order-hold signal
What does the spectrum of a sampled signal look like if one uses a zero-order-hold?
There is some information in:
Sampling theorem and Dirac comb, but I am wondering, how to apply this in practice.
...
0
votes
1answer
26 views
Random selection of sub-block in an image with matlab
I want to select a random sub-block of 8x8 out of an image 256x256. Is there an instruction that do this thing or i need to calculate it with a different approach. I found how to choose a galois field ...
-1
votes
0answers
71 views
bandpass implementing with DWT in matlab
In matlab help in find the implementation of bandpass as following
...
-1
votes
1answer
32 views
Getting Different Intensity Values in MATLAB and Java Program output
I am working in digital image processing field, i have set of mammogram images in .bmp format, when i am opening anyone image using MATLAB then i am getting intensity value as 0 for a particular ...
-1
votes
0answers
23 views
How to record voice in MATLAB to have nearly a same threshold value for every sample of the same word spoken? [closed]
We recorded 10 voice samples for a word, say 'hello'. Every time we calculated its threshold value, it differed from the previous one significantly. So we were unable to set a particular threshold ...
0
votes
2answers
118 views
Removing noise from audio using Fourier transform in Matlab
I'm trying to remove noise from an audio file. This audio file contains speech as well as constant pink noise. I know that I have to use the Fourier transform to convert to the frequency domain then ...
0
votes
2answers
80 views
Frequency array feed real values FFT
EDIT
The first version of my question has not worked as I expected, so that I will try to be a little bit more specific.
The final goal I am trying to achieve is the generation of a ten minutes time ...
-1
votes
0answers
30 views
signal seperation [duplicate]
I am want to separate music signal from the singer signal and eliminate the music once I do the transform using discrete wavelet but it don't know how can I sort it by frequency.
3
votes
1answer
61 views
Why is a feedback loop not represented by the least order transfer function?
I have a feedback loop with transfer $L(z)= \frac{H(z)C(z)}{1+H(Z)C(z)}$.
$H(z) = h$ and $C(z) = \frac{K}{z-\alpha}$.
If I manually calculate the transfer function, I get:
$L(z) = ...
0
votes
0answers
23 views
algorithm for audio and video separation using matlab [migrated]
sir
i want to design an algorithm which can take a movie clip or a video signal having both audio and video and extract the audio and video part separate using the help of filters, matlab and signal ...
2
votes
2answers
153 views
Even after applying a low pass filter, why is there a DC offset?
I need to smooth some data segments and one of the techniques I am experimenting is a low-pass filter. So I designed a low-pass filter in matlab and applied it to my signals. Here is what happened ...
3
votes
0answers
67 views
How exactly does MATLAB zeropad?
I am doing some massive number crunching in MATLAB which involves millions of PSD estimations. Each data segment has length 41. So I have been using the multi-taper method with nfft=41 (details below ...
0
votes
0answers
33 views
Detecting Regions of Constant Value
As an experiment, I have been trying to use cross-correlation to do approximate string matching. Specifically, I want to find the location of where a PORTION of one string (string A) is the ...
1
vote
2answers
67 views
generating ultrasonic sound in matlab
I am working for my class project on making animal repellent , I need to know how I could go about taking a normal audio file and shift its frequency/Pitch very high to make it an ultrasonic sound.
2
votes
0answers
58 views
Simulink continuous to discrete question
I'm new to Matlab/Simulink and would like to convert the continuous system below to discrete for eventual conversion to C code. Matlab has a c2d function, but I don't know how to apply it to a ...
0
votes
0answers
32 views
How to proceed for BOW creation From sift features
I extracted sift feature to construct a bag-of-words model. I did the following to extract the feature vector:
Extracted features from the key frames.
After the feature extraction I tried using ...
-6
votes
0answers
30 views
Reg: Sampling for Non band-limited Signals [closed]
I need a Matlab Code for Sampling of Non-Bandlimited Signals as a part of my project. Can Anyone help me out here by giving the code or any other way of getting it?
1
vote
1answer
82 views
Sampled signal reconstruction using matlab
I have a wav file recorded from my smartphone's mic, and I want to reconstruct the sampled signal and plot the reconstructed signal. After some research and search, I was able to get the following ...
-3
votes
0answers
48 views
code is supposed to draw epipolar line on graph: but not drawing any line, only showing points [closed]
i am trying to draw epipolar lines for certain point, from left image to right image plane. my code is supposed to draw epipolar lines based on fundamental matrix. but it is not drawing any line, i ...
1
vote
0answers
62 views
How to prevent Signal drifting when changing frequency
When I recreate a signal it seems to look great. But when I try and increase it's frequency (which is done in a for loop and the variable new_freq=2) it starts to drift.
See Image below (The top ...
2
votes
0answers
64 views
Any Good Image Blind Deconvolution Algorithm for Removing Camera Shake
I am working in digital image restoration field, i have images that are degraded by camera shake.. can anyone please suggest me any better non blind deconvolution algorithm.
my images are similar to ...
2
votes
1answer
58 views
obtaining “4 Hz modulation energy”
Could anybody tell me a method to calculate the "4 Hz modulation energy" for a speech signal?
Thanks.
EDIT
I get some details : 4 Hz modulation energy: Speech has a characteristic energy modulation ...
3
votes
2answers
97 views
2D FFT of Vector
I have a bunch of 8x8 images which have been vectorized and formed into a 64xN matrix, X. I'd like to take the 2D-FFT of each of these images without reshaping each column of X into an 8x8 image and ...
0
votes
0answers
37 views
Finger print skeletonization without using matlab functions
I am trying to thin foreground pixels of a finger print until they are one pixel wide without using the built in bwmorph and thin operations.
Can anyone explain to me how to write them in matlab ...
3
votes
2answers
87 views
Gaussian random generator
I have quite a straight-forward question. What I aim for is the generation of a certain set of random numbers with a normal distribution (mu = 0, ...
3
votes
0answers
41 views
Zero padding of mfcc coefficients
I am trying to implement speech recognition using backpropagation algorithm, and I have been following this paper http://research.ijcaonline.org/volume42/number12/pxc3877946.pdf.
I have followed it ...
4
votes
1answer
73 views
Discrete Fourier Transform a dummy approach
I'm trying to understand how DFT works exactly. However, when experimenting around, I compared both Matlab generated FFT result with a dummy approach result and I get similar result.
However, the ...
3
votes
0answers
83 views
Extra 'fingers' found in graph after applying FFT in MATLAB
I am currently working on the FFT function in MATLAB. In this function, i require a 1024 number of data Time Domain plot and produce a 400 number of data Frequency domain plot.
After applying the FFT ...
1
vote
0answers
29 views
Signal level estimation, matlab
Three methods of estimating maximum signal level at a node:
Worst Case Min-Max (L1-Norm)
Mean Square (L2-Norm)
Frequency Domain (Linfinity-Norm)
In matlab i found the code for L1, L2
...
1
vote
2answers
40 views
one-source signal separation
I have a wav file which is gained by playing 2 different wav files with 2 speakers and recorded with mic. If I want to get one of the original signals using the resulting wav file and the other ...
3
votes
1answer
72 views
How to compute dBFS?
I asked myself how to compute dBFS (dB full scale) from a value of sample between 1 and -1?
and in general?
0
votes
2answers
86 views
Estimating the time offset (delay) between two audio signals in real-time
I'm looking for an algorithm which can accurately estimate the time-offset/delay between two audio signals in real-time. One audio signal is a loudspeaker signal and the other signal is the microphone ...
1
vote
3answers
114 views
Generalized Cross Correlation
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 ...
6
votes
0answers
105 views
Counting vechicles in an image
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 ...
2
votes
3answers
98 views
Effect of windowing on FFT magnitude
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 ...
2
votes
1answer
81 views
Question about overlap-add
@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 ...
1
vote
1answer
34 views
Comparing multiple armax models
I would like to create an algorithm that, given an iddata, estimates different armax models with different na, nb, nc, nk, and finally it show the compare plot.
I know how to use the armax ...
5
votes
1answer
97 views
How to measure the agreement between to curves?
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 ...
3
votes
1answer
99 views
Why can the FFT always be mirrored in the middle of the x axis? [duplicate]
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 ...
1
vote
1answer
48 views
Frequency vector and fft
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 ...
3
votes
0answers
65 views
fit theoretical spectrum to simulated one
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 ...
2
votes
0answers
33 views
How to plot graph for coverage area
I have a two data set files data1 and data2 each containing 5000 points having 3 columns representing ...
0
votes
3answers
114 views
Finding the dominant tone in a signal
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 ...
