All Questions

0
votes
0answers
2 views

Extending a waveform

Apologies if this makes no sense or seems rather simple, I'm a Matlab newbie. Basically, I've got a .wav audio waveform which I am resampling to various different frequencies and then trimming the ...
0
votes
0answers
8 views

downsampling an fft signal

I am currently working with a set of wavelet transforms that I came across in a paper. The paper suggests that I first apply the FFT on the source image and then perform the downsampling. So it says ...
0
votes
1answer
20 views

Bandwidth of an energy signal

I'm studying for my midterm , and I'm struggling with finding bandwidths. I have this energy spectral density : $\Psi(f)= { 1 \over \sqrt { 1 + ({f \over B }) ^2} }$ , and I need to find the ...
0
votes
0answers
17 views

MATLAB MIRtoolbox - mirtempo function

I just want to know how functions like mirtempo(), which returns a mirscalar object to a direct format that MATLAB can ...
0
votes
1answer
13 views

Bluetooth locating with RSSI and only one receiver

Is there a method to find the relative direction of a Bluetooth device to the receiver? A quick Google search on "Bluetooth positioning" returns several methods using triangulation, but I don't want ...
0
votes
1answer
28 views

Noise in Digital image

in Digital Image Processing restoration ,from my understanding after reading articles , it's seems that the noise must be dominant in the histogram of the image , which is make it possible , to get ...
0
votes
0answers
11 views

problem in getting rank of matrix correctly

I have a equation to implement which result into the square matrix of orthogonal columns but non independent columns. The rank of this matrix does not seem to be correct. Can anyone help me? The ...
0
votes
0answers
14 views

state space formulation of a sinusoidal system

Let $f=A\sin{\omega t}=x_1$ and $\dot{f}=-A\omega\cos{\omega t}=\dot{x}_1=x_2$. Let the output be $y=cA\omega$, where $c=1$ is a constant. I want to represent this in a state space formulation: ...
0
votes
0answers
26 views

Merging pattern for FFT solutions

I have the generic problem of analysing a discretly sampled signal, lets say at 100Hz, and would like to compute features (ML application) of this signal at different scales: An instantiation of this ...
0
votes
1answer
15 views

Estimating signal strength from PCM-encoded signal

I am processing rtl_fm output (in time domain), extracting Manchester encoded bits. I can detect preamble and, therefore, decode the message which follows the preamble. This is how my signal looks ...
-1
votes
0answers
7 views

Calculating covariance in matching for KLT alorithm

Just would like to check out if there is any reference to the calculation of covariance for KLT image matching between two images THanks
0
votes
2answers
24 views

Relationship between Carrier Frequency Offset and the Constellation Diagram

As part of a project I am doing, I have to investigate how having a carrier frequency offset would affect the constellation pattern of the received signal.This question has got me baffled because to ...
-1
votes
0answers
6 views

Minimal DSP for video transcoding

I am new to DSP, even more - i am not even in DSP theme at the moment. But i need to understand the possibilities before starting. Problem is - i need to transcode video from 12mbps MPEG2 to any other ...
0
votes
0answers
13 views

calculating frequency spectrum using fft for video

How to process video with DFT/FFT - getting the frequency using PCO camera in c#,and how to interlink video frames with frequency transform.
0
votes
0answers
13 views

Could the X-Y resolution for a stereo camera setup be better than that of either of the cameras alone?

My understanding is that it shouldn't be different than the resolution of a single camera, since the actual X and Y coordinates of a point in space are defined from the point's image up to a scalar ...
0
votes
1answer
18 views

BCI project using EEG signals

I want to make a BCI project, based on EEG signals, to control a robot using the brain's P300 wave. I have read a lot of papers, which give me a wide knowledge on how to deal with those signals, but ...
2
votes
1answer
77 views

Sound quality with really high sampling rate, but really low bit depth with dithering?

This question is probably more for fun and theory, but how will the sound quality be, if you create a sound with really high sampling rate (like 192kHz) and really low bit depth (e.g. 3bit)? Can you ...
1
vote
0answers
26 views

Polygon Segmentation technique

I am working on Automated GUI components Segmentation problem. My Images are very simple as it has GUI components such as Buttons, text box and other polygons as you can see in the diagram (a). ...
0
votes
1answer
36 views

Given two waves, 441 Hz and 700 Hz, how many samples long is each wave's period if the sample-rate is 48 kHz?

The title says it all. I have two waves, Master and Slave. Master is at 441 Hz and Slave at 700 Hz. The sample-rate is 48 kHz. I want to know how to calculate the period of each wave in terms of ...
0
votes
0answers
32 views

What are the frequency components of a sampled signal after low-pass filtering?

A continuous signal $x_a(t)$ is a linear combination of sinusoids of frequency 250 Hz, 450 Hz, 1 kHz, 2.75 kHz and 4.05 kHz. The signal $x_a(t)$ is sampled at $f_s=$1.5 kHz, and the resulting digital ...
1
vote
0answers
64 views

DSP interview question: use of the identity in development of a significant transform

I'm preparing interview and found this question. But I don't really understand what is the question. Does it ask about Fourier transform or Z transform? How the simple identity $$xy=\frac{1}{2}x^2 ...
0
votes
0answers
33 views

Find similarity of sound signal

So I was working on a program to comparing the similarity between the pronunciation of a word, First I got the audio file, and I use FFT on it to get the amplitude over frequency array, then I just ...
1
vote
0answers
28 views

MATLAB implementation Spline Fitting

Check the attached problem please. I am a beginner in spline fitting and have a few questions: 1) How to find the coefficients $c[n]$. Is it by DTFT? 2) I understand how to find the derivative but ...
-1
votes
1answer
41 views

Matlab Neural Network toolbox

Is there any way to use as single input an image (256x256 pixels) and get output of single value using Matlab neural network toolbox
0
votes
2answers
48 views

Multitone signals with low crest factor

I am trying to generate a multitone signals with low crest factor and as suggested in the Boyd's paper I am using the quadratic phase distribution: $Phase(k) = \pi(k - 1)(k - 1)/N$ where $N$ is the ...
0
votes
1answer
29 views

Perfect reconstruction ( Single Channel )

I was trying to solve the following problem . Given an input x[n], consider upsampling by 2, followed by interpolation with a filter having z-transform H(z) for magnification of the signal. ...
0
votes
1answer
23 views

Downsampling MP3 for FM broadcast

I have some MP3s that are encoded at 44.1kHz with a bitrate of 160kbps. I hook these up to my car using an FM transmitter and the sound quality isn't particularly great. Low and high notes sound ...
-1
votes
0answers
27 views

Filter design using inverse dft

How do I get the cut-off frequency? A filter is needed to recover $x_2(n)$ from the signal: $$x(n) = x_1(n) + x_2(n) + x_3(n)$$ where: $x_1(n) = \sin(0.5n)$ $x_2(n) = \sin(1.4n)$ ...
0
votes
0answers
12 views

Bundle Min Hashing for Logo Recognition

In reference to the paper Bundle Min Hashing for Logo Recognition: Suppose we have bundles {2,5,18,444,678} and {2,5,79,368,841} and the vocabulary size is 1M. If we have just 1 sketch per bundle ...
-1
votes
0answers
10 views

Explaining of lost probalbity over random loss channel

I am reading a paper about packet loss probability over random loss channel. In this paper, the author give a equation about loss probability as $(1)$. However, I cannot understand the meaning of it. ...
0
votes
2answers
26 views

Filter design / Analysis apps

There are a plethora of tools, both commercial and free, which I have found online for designing filters. The ones I have tried (so far) prompt for frequency response, number of steps (for FIR), then ...
0
votes
2answers
30 views

Why is successive decomposition of a signal performed only on low pass component?

The question says it all. In typical (wavelet-like) decomposition of a signal, why is only the low pass component chosen for successive decomposition ?
1
vote
2answers
30 views

Map time difference between two similar videos

Question: Is there any software, source-code, or well documented and easily implementable research (I am not afraid for a little bit of Python) to do the following: Take two similar videos from ...
1
vote
1answer
57 views

Removing frequency using FFT

So if I were to have an $n$ length sample of a given sample rate and were to run it through an FFT, resulting in $n$ complex elements. How would I obtain the frequency bins, such that if I know the ...
0
votes
0answers
28 views
+50

Are discrete wavelet transform based statistical features invariant to rotation/translation/scale?

I'm reading a paper where image classification is done. Their approach is to use the discrete wavelet transform with bi-orthogonal wavelets of degree 3.5 and decomposition of level 3 on images. Based ...
1
vote
1answer
61 views

Why these harmonics always present?

I am using Audio Precision 2700 to test some test vectors. I have connected resistor banks as class - d power amp's load, and tap from this resistor using a XLR cable to the AP. When my power amp ...
-2
votes
0answers
17 views

Frequency upconversion problem!

I want to upconvert the frequency signal of 16KHz bpsk modulated to 70MHz but the problem is an Rf ic mixer does'nt respond to such a small input signal!!!! so what should be the alternative as ...
0
votes
2answers
39 views

What is the difference between pitch detection and Onset detection?

According to wikipedia Onset detection: Onset refers to the beginning of a musical note or other sound, in which the amplitude rises from zero to an initial peak. It is related to (but ...
0
votes
0answers
20 views

Some questions about the cube map representation

I am reading a text about cube map representation, but it seems I am confused. How the cube map representation can be used to detect lines using $xn_x+yn_y-d=0$? (we can ignore the polarity of lines.) ...
0
votes
0answers
28 views

generating a waveform in matlab for rohde and schwarz signal generator

We are doing a test which consists in sending a waveform from Matlab to the signal generator SMB100A and sending it through a cable to the r&s spectrum analyzer just to have a channel. We set the ...
0
votes
0answers
24 views

Which values do I use to filter a specific frequency with an RLC circuit?

I have a RLC circuit with transformation $$H(s) = \frac{R}{Ls+\frac{1}{Cs}+R}$$ and I know that by setting $s=j\omega$ I can obtain the frequency response of this system. What I don't understand is ...
0
votes
0answers
20 views

What equation describes black alpha on a white image?

What equation best describes the alpha content of a black colored pixel applied to a white pixel when measuring the resulting pixel intensity? For instance given a white pixel: argb : 255, 255, ...
-1
votes
1answer
26 views

Hanning Window Formula - Matlab didnt work

Im trying to do the Hanning Window manually but didnt work, what Im doing wrong? t=[0:.1:10]; x=.5-.5*cos(2*pi*t/102); plot(x); Not sure why I cant obtain the ...
0
votes
0answers
25 views

0 accuracy on test data with 24 MFCCs

I have designed a classifier for "bols"(strokes) of the tabla, using the MFCC coefficients 2-13 (ignoring the first coefficient.) at the onsets. When I do a cross validation, I get approximately 46% ...
0
votes
0answers
11 views

how could i fill missing data?

i tried a forecasting method and i want to check if it is correct or not and why? my study is about evaluating mutual funds for two kind of them it is a comparative study and i wan to use gcc index ...
0
votes
0answers
14 views

Best segmentation method

This is part of my samples ...
0
votes
0answers
22 views

What's $\omega _n$ difference between Matlab and Mathematica?

I want to plot this Butterworth filter's TransferFunction: ...
0
votes
0answers
13 views

Symmetry of Walsh matrix

Walsh matrix is abtained by sorting the rows of Hadamard matrix by number of sign changes (1st row had 0 changes, 2nd has 1 change of sign etc). Walsh matrix is symmetric. Meaning the sorting the ...
0
votes
0answers
23 views

Image enhancement algorithms for adjusting shadow, exposure, contrast etc

For those who have either used Picasa/Photoshop, they would see different image enhancement options such as: Change exposure Change shadow Change highlights Change vibrance I have searched online ...
0
votes
1answer
29 views

Feature vector for MFCCs

I am working on a project, for which I am finding the onset times of an audio and then extracting the MFCC coefficients for all the times. Thus if I have n onset times, I would have n feature ...

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