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satish_sac - 2007-08-07 07:26:00
Hi, I am looking for an Deconvolution algorithm to restore an image by
deconvolution of image data and its known/modeled PSF. Which algorithm is
best suited for this? Is it available on the net.
Regards,
Satish
...
Vicki - 2005-02-23 10:27:00
Hi all,
I'm looking for some background on blind deconvolution -- mainly as I'm
going to have to explain it to a group of medics and non-engineers.
I've got the Simon Haykin, Unsupervised Adaptive Filtering: Vol 2 book.
Are there any other books or papers that deal in general terms with
blind ...
anthony - 2006-03-31 07:18:00
In my understanding, the deconvolution process with FFT is to use divide
operator instead of the deconvolution operator, that is
---aries44's post-----------
In order to convolve two functions 'a' and 'b', we can take their Fourier
Transform(FT) and multiply them in Fourier domain i.e.
C= FT(a) ...
amit - 2004-01-30 04:17:00
hello,
i am working on project of x-ray diffractometer.
Basically the type of distribution for x-ray pattern is poisson type.
i want to know the names of the algorithms which can be used for peak
deconvolution on x-ray diffraction patterns and the link of the site
or documents which describ...
aumi4 - 2006-03-08 14:56:00
hi ppl,
I am doing my final year btech project and am stuck at the below...
i have two matrices and i want to find the third one.All are of the same
dimesntions.
M(f) = R(f) * W(f)
The product is the convolution.
i know M(f) and W(f)
I want to find R(f)
I basically want to perfor...
I would like to get some feedback on this idea. Multiplying
a signal in the time domain by a window before computing its FFT
is equivalent to the convolution of the transform of the signal
with the transform of the window.
It seems therefore that one could "undo" the effect of a square
window (...
ramjanagam - 2009-11-03 13:15:00
Hi every one
I am working on Wiener deconvolution. my aim is to deconvolve the
refelectivity function. I am using threshold method in inverse filtering
for the deconvolution.
Hf = H.*(abs(H)> 0)+1/gamma*(abs(H)==0);
iHf = 1./Hf;
iHf = iHf.*(abs(H)*gamma> 1)+gamma*abs(Hf).*iHf.*(abs(Hf)*...
ekomninos - 2008-02-28 06:46:00
Hi,
I have available input and output data and type of noise(mean , dev) i
want to use the deconvolution algorithm in order to estimate AR coefs but
i can't find anything relative to this algorithm.I have used so far
projection,orthogonalized projection and rls algorithms for doing so but i
can't...
charanchar - 2009-03-17 12:57:00
hi please help me on this
x(t)=sin(2*pi*10*t);
w(t)--> awgn noise
y(t)=x(t)*e(j*w(t));
here x is multiplied with e(j*w) in time domain. that is equivalent
to
convolution if frequency domain
how to estimate e(j*w(t)) using deconvolution in frequency domain?
...
I did a deconvolution between two signals, a sweep and an impulse
response (actually an impulse response with a very simplified response,
I lowpass filtered its magnitude bins in the frequency domain to make
it smooth) and as a result, i get what I expect, plus a weird peak
(actually two very cl...
gokul_s1 - 2006-07-12 10:16:00
Why is the inversion of a Toeplitz system Ax=b, where A is a Toeplitz
matrix, ill-posed even when A is not rank deficient?. If A is full rank,
shouldnt the system have a unique solution and not be affected by small
noise perturbations?. How can one relate the ill-posedness of
deconvolution problems ...
In order to convolve two functions 'a' and 'b', we can take their Fourier
Transform(FT) and multiply them in Fourier domain i.e.
C= FT(a) * FT(b)
c = IFT(C)
and then Inverse Ft(IFT) of 'C' gives us the convolution of 'a' and 'b'.
Now if we want to deconvolve 'a' from 'c' to get 'b' we can do
...
Jerry Avins wrote:
(snip)
> How do you make a digital filter non-linear without saturating? A truly
> non-linear filter doesn't have a single impulse response. I suppose that
> a liberal interpretation of "filter" would include squaring and
> transcendental functions, but that doesn't s...
emre - 2006-12-22 23:28:00
Hi there,
I want to find the minimum phase spectral factor of a real autocorrelation
sequence using cepstral deconvolution. However I run into problems when the
spectrum has a null. Is there a way to get around this problem, or is the
cepstral deconvolution doomed to fail in case of a null? Could...
I am trying to improve algorithms to apply the BLIND DECONVOLUTION to
the real data as for example to eliminate the effect given by an
environment on a vocal(speech) signal.
Currently I possess some algorithms that I would like to improve.
For this I desire to exchange knowledges, data and alg...
2006-07-21 16:22:00
Hello, all.
I have a dilemma. I'm analyzing some time signals for periodicities,
and I was wondering about a seemingly basic method of doing it. I hope
you'll forgive my ignorance, as my specialty is physics and not signal
processing :P
So, we have a time-series that is the product of a s...
Fokko Beekhof - 2008-02-25 05:37:00
Hello,
I'm trying to understand the Richardson-Lucy deconvolution algorithm,
primarily from the description here:
http://en.wikipedia.org/wiki/Richardson-Lucy_deconvolution
In this notation, u_i is a pixel in the latent image(unknown), c_i the
corresponding pixel in the observed image, and ...
2005-11-07 15:25:00
Julian Stoev wrote:
> Hello Christian,
>
> Your approach is based on the assumption, that P(k) is FIR filter? I did
> not mention it, but I used P(z). ;-)
>
> My case is related to IIR description of the system. For example
>
> 5.641e-006 z^3 + 0.1712 z^2 + 0.8146 z - 0.0...
Midhat - 2008-08-07 12:57:00
Hi,
I have a question regarding the deconvolution of a signal from the window.
we had non-equispaced vlbi data, to do the analysis we first windowed the
data in the time domain using parseval window then applied SVD and DFT in
order to get the power spectrum in the frequency domain. But using the
p...
Andor - 2005-04-12 04:52:00
Ulrich,
if the crosstalk is linear and time-invariant, you can try to subtract
the crosstalk via deconvolution. You need to find the crosstalk filters
c_12 and c_21 (look up deconvolution to find out how). Then first
approximation of the cleaned up signals is
s1' = s1 - c_21 * s2
and
...
jddaviswy wrote:
(snip)
> I don't think that anybody else has mentioned this so I will put my two
> cents in here. The kind of resolution that people are talking about
> when they say that you can't get any more by zero padding is the
> ability to resolve two very close tones. If you ...
Joerg wrote:
> > All you need is gain and freedom from noise. Freedom from noise is the
> > hard part, but as Stephan Bernsee once wrote, papier ist duldig (paper
> > is patient-- read "compliant").
> When Germans say "Papier ist geduldig" they often mean "It looks easy on
> paper...
mistvan wrote:
mistvan wrote:
> I am trying to implement a linear convolution of FIR IR and a
> large input sequence. The IR is symmetrical (L=11).
> I receive the data in frames of say 128 samples (could be less
> or more than this). The output exhibits problems at the f...
Michel Rouzic wrote:
> Here's the problem, due to the overwhelming presence of black areas in
> my pictures, it leaves FIRs with negative values (such as Lanczos/
> windowed sinc FIRs) out of the equation (well it at least makes them
> far-from-ideal choices), as most of the time the resul...
sofiyya - 2009-09-23 07:24:00
Hi,
I have a problem with vector deconvolution. This is what I do in Matlab:
> > vect1=[1 2 3 4 5 6 7 8 9];
> > vect2=[1 2 3 4 0 0 0 0 0 0 0 0 0 0]; %I want to find w with
conv(w,vect1)=vect2
> > Lx=length(vect2)-length(vect1)+1;
> > Lx2=pow2(nextpow2(Lx));
> > VECT1=fft(vect1,Lx2);
...
sofiyya - 2009-09-23 07:25:00
Hi,
I have a problem with vector deconvolution. This is what I do in Matlab:
> > vect1=[1 2 3 4 5 6 7 8 9];
> > vect2=[1 2 3 4 0 0 0 0 0 0 0 0 0 0]; %I want to find w with
conv(w,vect1)=vect2
> > Lx=length(vect2)-length(vect1)+1;
> > Lx2=pow2(nextpow2(Lx));
> > VECT1=fft(vect1,Lx2);
...
Oli Charlesworth - 2007-09-20 09:40:00
On Sep 19, 10:50 pm, "riz" wrote:
> > On Sep 19, 4:16 pm, "riz" wrote:
> > > > On Sep 19, 9:49 am, "riz" wrote:
> > > > > Out of convolution operation and inverse filtering operation,which
> > > > > operation is better regarding the stability point of view(minimum
> > > phas...
Les Cargill - 2009-10-31 19:54:00
Frédéric Jolliton wrote:
> Hi,
>
> I'm looking for a method to automatically synchronize various audio
> tracks, recorded at the same place, with different devices. This is
> intended to work at post-processing time (not in realtime.)
>
> Basically, I'm taking two audios track: one...
lucy wrote:
> I have a filter and want to inverse the filtering step, what can I do?
See: Deconvolution of Images and Spectra
by Peter A. Jansson
-- glen
...
Hello,
I am trying to model the behaviour of a reactor vessel when some
particles inside the container strike the inner wall using FINITE
ELEMENT MODELLING software.
I reproduced several random particles hitting the wall at different
times and position across the surface of the inside wall....
Hello,
I am trying to model the behaviour of a reactor vessel when some
particles inside the container strike the inner wall using FINITE
ELEMENT MODELLING software.
I reproduced several random particles hitting the wall at different
times and position across the surface of the inside wall....
BCC wrote:
> Hi,
>
> Can anyone tell me what this code means, or what kind of filter it may
> be representing?
>
> const double std_spike_sym_delta[] = {-4, +4, +1, 0, -1, -4, +4};
> const int std_spike_sym_width[] = {1, 1, 2, 2, 2, 1, 1};
> const int std_spike_body_widt...
Hi,
I am really new to this so bear with me. I got a homework assignment for
a course called analytical topics and I was wondering if anybody could
help me figure it out. I don't need a complete answer but just some
pointers of where to begin with this problem and how to proceed. Thank you
very mu...
Hi All,
I am working with injecting contrast/dye and measuring the resulting
enhancement (resulting from the injection) in a patient.
The injection is a square input (e.g., 20 ml @ 4 ml/sec for 5 sec). Now,
I measure the resulting enhancement (OUTPUT) at a certain location. Now,
this outpu...
Oli Charlesworth - 2007-04-20 16:21:00
philgo said the following on 20/04/2007 19:23:
> Let me try to rephrase the question.
>
> In traditional beam-forming, we are always talking about angles, angle of
> arrival, angle of departure, beam pattern pointing to a certain angle,
> etc.
> However, when we talk about the MRC, the ...
Andor wrote:
(snip on non-uniform sampling and aliasing)
> However, it is obvious that one can still find sine waves at other
> (higher) frequencies that _will_ pass through those points in Fig. 5.2
> (I calculated this myself, using randomly selected samples of a sine
> wave). It seems l...
Ron N. wrote:
(snip)
> That's the heart of a semantic problem when discussing band
> limited signals. People sometimes (often?) confuse
> bandlimited signals with low-pass-filtered signals. But a
> truely and perfectly bandlimited signal actually implies
> constraints on the distant f...
2008-08-10 00:07:00
Hello-
Disclaimer: I have no background in optics or image signal
processing, so I apologize in advance for abusing any terminology. I
just discovered this list via Google, and I hope that some of you
might be able to help point me in the right direction. Here goes...
I'm working on a so...
HardySpicer - 2009-09-06 19:56:00
If I have a random signal u(k) and a (known) transfer function H then
y(k)=Hu(k) and if I know H and H is minimum phase then I ca neasily
find u(k).
Suppose H is nonminimum phase eg
y(k)=u(k)-2u(k-1)
how to get at u(k)? Can I run time backwards in some way so the H is
stable in rever...
HardySpicer - 2009-05-06 22:05:00
On May 7, 11:53=A0am, "sauwen" wrote:
> Once you filter a signal, what is the best way to get the original signal
> back?
>
> Thanks..
Deconvolution is the way - at least optimal in the sense of least
squares.
Hardy
...