Signal Processing Weekly Newsletter - Friday, January 30, 2015

Signal Processing newsletter

Top new questions this week: Difference between Digital signal and Discrete signal I have just started studying Digital Signal Processing. Can someone explain what is the difference between a Discrete Signal and a Digital Signal in simple words? Thanks in advance ! discrete-signals digital   asked by praghu 4 votes answered by Talasila 7 votes Deriviation of the "Twiddle Sum" property I can't seem to understand how to derive the "twiddle sum" property: $$\sum_{n=0}^{N-1}W_{N}^{kn}=N \ \delta[k\bmod N] $$ where $$ W_{N} \triangleq e^{\frac{j 2 \pi }{N}} $$ and $$ \delta[n] ... dft math derivation   asked by Mike 3 votes answered by Matt L. 6 votes Unable to calculate the CRLB for Gaussian mixture model I am unable to follow the steps needed to derive the Fisher Information matrix and the CRLB of an autoregressive model from the observations $x$. The AR process is excited by non-Gaussain sequence, ... discrete-signals estimators   asked by Srishti M 3 votes Velocity estimation knowing acceleration and displacement from measurements using Kalman filter I am having a hard time in trying to use a Kalman filter to obtain velocity from acceleration and position measurements. I think the main reason is that I am not familiar with Kalman filters (I had ... matlab kalman-filters   asked by Rhei 2 votes Clarification about wavelet thresholds I am trying to wrap my head around the original wavelet shrinkage papers of Donoho and others from the mid-90s. There are a couple of curious things that confuse me, and I'd appreciate some input: ... wavelet thresholding   asked by user32849 2 votes Real-time block processing setup on ARM newbie question here. im working on a system thats running 32khz sampling rate, audio, 16 bit dac. currently our system had a very hard latency requirement of 1 sample. so no problem, we read 1 ... fft dsp-core adc   asked by Anthony Parks 1 vote answered by pichenettes 1 vote Is there a better Fourier Transform-based algorithm to use in Image recognition I have been trying to use the Fourier transform in recognizing images of the same size 200x400. I have tried many different ways to do that such as: Performing the Fourier on the full image and ... image-processing matlab fourier-transform algorithms   asked by Alladin saoudi 1 vote answered by Peter K. 1 vote Greatest hits from previous weeks: What does frequency domain denote in case of images? I was just learning about the frequency domain in images. I can understand the frequency spectrum in case of waves. It denotes what frequencies are present in a wave. If we draw the frequency ... image-processing frequency-spectrum dft   asked by Abid Rahman K 51 votes answered by nikie 59 votes Deconvolution of 1D signals I have convolved a random signal with a a Gaussian and added noise(poisson noise in this case) to generate a noisy signal . Now I would like to deconvolve this noisy signal to extract the original ... matlab continuous-signals 1d   asked by user1724 6 votes answered by Andrey 10 votes Can you answer these? Claim: Given sampling time T, the hold operator is approximated at low frequency by a time delay of T/2 Can someone verify this statement? The hold operator is assumed to be a zero order hold Then the laplace transform of this hold operator has a well known form $(1-e^{-sT})/s$ Let w approach 0, we ... sampling z-transform laplace-transform   asked by Illegal Immigrant 1 vote Morphological gradient versus linear gradient To obtain the gradient from an image, one can use a linear filter that for example is derrived from the derrivative of a gaussian. Then convolving the image with this linear filter gives you the ... filtering morphological-operations gradient   asked by Tom 1 vote (python+opencv) haar cascade training using cloud computing I will train my own cascade, using python and opencv. I want it to be as precise as possible, so as I read it is common that training takes one or two weeks to compile. I want to use cloud computing ... python   asked by talha 1 vote

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