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15 votes
Accepted

Does a simple photograph contain more information than a complex painting?

It depends how you define the term "information" or "entropy". The conventional definition of entropy of an image is to think the image as a two-dimensional matrix of pixels and $$H = - \sum_k p_k \...
AlexTP's user avatar
  • 6,595
8 votes
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How does the assumption that symbols are equi-probable hold

If I draw a number uniformly between zero and one, what is the probability that they are equal? Mathematically, it should be zero but I don't recall why? Can somebody please help in explaining why ...
AlexTP's user avatar
  • 6,595
5 votes

Why expected value is optimal?

Nothing is "optimal" in an absolute sense. Something is or is not optimal according to a defined, precise criterion. Say you have a real random variable $X$. You want to find a number $m$ ...
MBaz's user avatar
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3 votes
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Seeking compressive sensing imaging demo in MATLAB

You can start with the Compressive Imaging Code code by J. Romberg, illustrating the paper "Imaging via Compressive Sampling". Another great source of information and codes is on Nuit Blanche.
Laurent Duval's user avatar
3 votes

What are your tips for DSP self-study?

DSP would be a quite broad subject and where to start would depend on your ability to pick up information, learn, understand and implement it. A basic course for supplying us with the basics to ...
Disciple's user avatar
3 votes

What Resources Are Recommended for an Introduction to Signal Processing (DSP)?

I would add to the list the book "Digital Filters", by Richard Hamming. A short classic, rather than a heavy tome.
2 votes

Seeking compressive sensing imaging demo in MATLAB

The following links have papers and usually have the associated code: l1 magic Rice University SparseLab SPGL1 Hope that helps.
David's user avatar
  • 2,861
2 votes

What Resources Are Recommended for an Introduction to Signal Processing (DSP)?

https://www.amazon.com/dp/B01MS8W9XI This book will go through different projects that will teach the reader how to write software: to improve their singing, synthesize different guitar sounds, ...
2 votes

Does a simple photograph contain more information than a complex painting?

Based on your provided images, the painting should involve more information. However, the sky scene might include perceptually invisible components that a mathematical algorithm would treat as ...
Fat32's user avatar
  • 28.2k
2 votes

Origin of brightness artifacts in intensity resolution compressed images

I've taken the original tiff and just set a low threshold for 1bit quantization (conversion to black and white): so we can clearly make out that these artifacts look very circular, and placed in ...
Marcus Müller's user avatar
2 votes
Accepted

Can we band pass filter QPSK signal?

Yes, you can bandpass the QPSK signal before matched filtering and demodulation if you wish to do so, but what you need to devote some thought to is whether such an action is a wise decision. The ...
Dilip Sarwate's user avatar
2 votes

Overview Noise Reduction Techniques

The frequency domain conjugate multiplication (correlation) of the received signal with the reference signal followed by the power delay profile will provide you the overall signal to noise ratio. As ...
Sagar Salwe's user avatar
2 votes

Matched Filters for attenuation detection?

Your interpretation of the matched filter for radar seems almost right, just to be sure, let me reiterate a bit: Think of it this way: we're sending a pulse function $p(t)$. If a target in distance $d$...
Florian's user avatar
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2 votes
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From Mathematics to DSP

In general, Maths to audio signal processing is a very natural progression. I seem to recall my Master's and PhD supervisors both did their undergraduate degrees in Maths. To your questions: This ...
tobassist's user avatar
  • 816
2 votes
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Given a impulse responce can we derive a state space model?

you might need some procedure like the prony method to convert your impulse response (as a bandlimited and uniformly-sampled signal) into a sum of decaying exponentials and from that obtain a sum of ...
robert bristow-johnson's user avatar
2 votes
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Does 46 dB gain of a filter for a frequency imply 200 times more amplitude?

can we expect to get 200 times higher amplitude in the output of the filter comapre to the input of the filter Yes. For a sine wave input the amplitude of the steady state output is simply the ...
Hilmar's user avatar
  • 44.8k
2 votes

What helped you in reading and implementing papers and coming up with original ideas in computer vision/graphics?

People working in computer vision/graphics may have very different backgrounds: computer programming, high-performance computing, signal processing, image analysis, optimization, machine learning, etc....
Laurent Duval's user avatar
2 votes

Radar type application for narrow band only?

These constraints absolutely exist. There are the norm! We could only wish in our wildest dreams to use as wide as bandwidth as we like. There are many areas in a radar system that place limitations ...
Envidia's user avatar
  • 2,531
2 votes
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What do you call the random Gaussian vectors in compressed sensing?

The collection of scalar products is often called measurement. The collection of vectors (each being an atom) can be called measurement dictionaries or sensing dictionaries. This is not specific to ...
Laurent Duval's user avatar
2 votes

What do you call the random Gaussian vectors in compressed sensing?

In most of the literature I am familiar with (signal processing), these vectors are considered collectively as rows in a matrix, i.e. $$\mathbf y = \mathbf E \mathbf x$$ where the $(M \times 1)$ ...
Thomas Arildsen's user avatar
2 votes

Fourier Transform of the conjugate of a complex function

$\mathcal{F}\{x^*(t)\} = X^*(-f)$ Taken from the table of Fourier transform theorems on slide 6 of this document: https://www.comm.utoronto.ca/~dkundur/course_info/316/KundurFTProperties_handouts.pdf ...
shredEngineer's user avatar
1 vote

Is there a noise cancellation technique for over-lapping spectra?

First of all the Wiener filter does not remove the noise but reduce it for WSS signals. It does this based on the relationship between the power spectral density of the clean signal $x[n]$ and ...
Fat32's user avatar
  • 28.2k
1 vote

Why do mobile phone calls produce a vibration when they are near a speaker?

The Global System for Mobile Communications (GSM) is a 2G (2nd generation) technology which uses the time division multiple access (TDMA) method. With this method, each phone transmits within its own ...
Olli Niemitalo's user avatar
1 vote

Why do mobile phone calls produce a vibration when they are near a speaker?

A little background... How a speaker works: Speakers are controlled by driving small diaphrams with a magnet and that magnet is controlled by wires that take isolated 'wired' signals and convert them ...
Dr. Dan's user avatar
  • 119
1 vote

System Response Terminology

$$ x(0^-) \ \triangleq \ \lim_{0<\epsilon \to 0} x(-\epsilon) $$ using the traditional undergraduate one-sided definition of the Laplace Transform, $$ \mathscr{L}\Big\{ x(t) \Big\} \triangleq X(s)...
robert bristow-johnson's user avatar
1 vote
Accepted

System Response Terminology

Assuming that you denote the output by $y(t)$ and the input by $x(t)$, the initial conditions are given by the values of $y(t)$ and its derivatives at a certain time $t_0$ (choose $t_0=0^-$ if you ...
Matt L.'s user avatar
  • 90k

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