Signal Processing Weekly Newsletter

Signal Processing newsletter

Top new questions this week:

How to classify accelerometer data?

I am trying to detect if a car did accelerate or did brake by using the accelerometer of the iPhone. In the figure below I plotted the collected data. (To collect the data the phone was laying flat …

signal-detection classification detection  
asked by riik 4 votes

Adaptive Equalizer for IIR channel?

I am quite new to the idea of equalization. I have a few queries regarding the same. In my application I require to equalize a channel whose impulse response is an IIR response. Is it possible to …

adaptive-filters adaptive-algorithms equalizer  
asked by rsashwinkumar 3 votes
answered by Matt L. 6 votes

Why does the DFT assume the transformed signal is periodic?

In many signal processing books, it is claimed that the DFT assumes the transformed signal to be periodic (and that this is the reason why spectral leakage for example may occur). Now, if you look at …

discrete-signals signal-analysis dft  
asked by user10839 3 votes
answered by Matt L. 4 votes

The small red peak in the CIE standard observer

The human eye has 3 types of color cones: red, green and blue. Their spectral sensitivity peaks in short (S, 420–440 nm), middle (M, 530–540 nm), and long (L, 560–580 nm) wavelengths. See diagram …

image-processing computer-vision color  
asked by Julian 3 votes
answered by jojek 2 votes

please give the reason why every notation for DFT is valid?

$X$ represents sample in frequency domain and $x$ represents samples in time domain. NOTATION 1 $ X[k] = \sum\limits_{n=0}^{N-1} x[n] \ e^{-j \frac{2\pi}{N} n k} $ $ x[n] = \frac{1}{N} …

asked by Vineel Veludandi 2 votes
answered by Matt L. 2 votes

How to detect whether the object has triangular shape?

The task is to detect arrow from medical images. After segmenting, arrow-like objects can be connected with other connected components (noise). In this context, detecting a part of the object that …

image-processing computer-vision  
asked by Santosee 2 votes
answered by dhanushka 1 vote

Why is LBP generaly faster than HAAR?

I am digging into Haar like and LBP features. More precisely its implementation in OpenCV. Every article or forum entry I found states, that LBP is faster than Haar. My local tests also confirm this …

opencv local-features detection  
asked by user10861 2 votes

Greatest hits from previous weeks:

Can we break the Shannon capacity?

I have a friend working in wireless communications research. He told me that we can transmit more than one symbol in a given slot using one frequency (of course we can decode them at the receiver). …

modulation reference-request channelcoding  
asked by Learning 7 votes
answered by jan 15 votes

Difference between correlation and convolution on an image?

Could you please clearly explain what is the difference between correlation and convolution that is down by a filter on an image? I mean in terms of signal processing definition I know that …

image-processing convolution image correlation  
asked by the_naive 3 votes
answered by Dima 6 votes

Can you answer these?

Ways to find three curves from palm image

I am asked to extract three curves from palm images. original image expected result. The curves has lower intensity than neighboring pixels. So I try to …

image-processing matlab image-segmentation  
asked by Jogging Song 1 vote

How to replace Hadamard Product and Column wise addition with new Matrix operation?

Let $$ A= \begin{bmatrix} a_{1,1} & a_{1,2} & a_{1,3}\\ a_{2,1} & a_{2,2} & a_{2,3}\\ a_{3,1} & a_{3,2} & a_{3,3}\\ \end{bmatrix} $$ and $$ B= …

signal-analysis matrix  
asked by Mithun 1 vote

Implementation of the constant Q transform + property questions

I'm reading up on fourier theory, especially the transforms. I implement the math as spectrograms in C++ to get a better understanding of what is going on. I've made an implementation of the short …

fourier-transform software-implementation  
asked by Shaggi 1 vote
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