Convolution between A(t) and S (t) is defined as integral (-infinity to +infinity) with inside integral we have A(T)S(t-T)dT, now suppose...

Convolution between A(t) and S (t) is defined as integral (-infinity to +infinity) with inside integral we have A(T)S(t-T)dT, now suppose if we have A(T)S(vt-vT) inside that intergal, where 'v' is a constant. Can we still call it as a convolution? if yes how can we take care of 'v' and if its not a convolution how can we manipulate it to make it convolution? This message was sent usi...

I think I'm missing something basic. http://mathworld.wolfram.com/Convolution.html defines convolution as "A convolution is an integral that...

I think I'm missing something basic. http://mathworld.wolfram.com/Convolution.html defines convolution as "A convolution is an integral that expresses the amount of overlap of one function g as it is shifted over another function f. ..." So what is difference between convolution and correlation?

"brent" wrote in message news:0fd6f825-e7ad-4642-a5fe-83de8ff8f7f6@x18g2000vbd.googlegroups.com... > I have created a tutorial on the...

"brent" wrote in message news:0fd6f825-e7ad-4642-a5fe-83de8ff8f7f6@x18g2000vbd.googlegroups.com... > I have created a tutorial on the convolution integral. It uses an > interactive flash program with embedded audio files. > It is located here: > http://www.fourier-series.com/Convolution/index.html You start off by saying that convolution is a mathematical operati

Hello forum, another basic questions, but you experts are better than any book. Give two finite sequences X and Y of duration, respectively...

Hello forum, another basic questions, but you experts are better than any book. Give two finite sequences X and Y of duration, respectively N and M samples, the convolution will be a new sequence G of length M+N-1 samples. that said, what is the wraparound error? The discrete convolution assumes that both X and Y are periodic sequences. (That way we can approximate the convolution ...

Hi all, I am helping a friend on this. We would like to evaluate the convolution of f(x)=exp(3 * x) / (1 + exp(x) ^ 5). However, in...

Hi all, I am helping a friend on this. We would like to evaluate the convolution of f(x)=exp(3 * x) / (1 + exp(x) ^ 5). However, in Maple and Mathematica, using symbolic calculations, the convolution results in numerical oscillation (lots of spikeness). We don't know why. We just couldn't get rid of the spikeness. And we thought at the end of day, our end-goal is to numerically evalua...

Hi, Convolution in time domain is equal to multiplication in Frequency domain. I am using convolution in neural network. As many papers...

Hi, Convolution in time domain is equal to multiplication in Frequency domain. I am using convolution in neural network. As many papers says that converting image and weight matrix in frequency domain, multiply and inverse the result will take less process time comparable to convolution in Time domain. But the process time is increased instead of decreasing in my program. I have given the d...

Hi everyone, I'm currently a student studying electrical engineering at University so I'm new to both these forums and the subject of DSP in...

Hi everyone, I'm currently a student studying electrical engineering at University so I'm new to both these forums and the subject of DSP in general. I would just like to ask how can I compute the circular convolution of the two sequences: {x(n)} = {4,3,2,1} and {h(n)} = {5,6,7} I know how to compute the linear convolution, but I am stuck as to how to do the circular convolution.. Co...

I have the knowledge of fourier transform of the circular convoluion of two vectors say h and s, ie i know FFT (s ** h) [saying ** stands for...

I have the knowledge of fourier transform of the circular convoluion of two vectors say h and s, ie i know FFT (s ** h) [saying ** stands for circular convolution]. I want to know FFT of linear convolution of s and h ie my target is to calculate FFT(s*h) [where * is the linear convolution]. I neither know s nor h. Is it possible and if yes then how?

Hi, I have implemented 1D convolution in many ways before, in the time-domain, by FFT, or by FFT with overlap-add, but I have never did that...

Hi, I have implemented 1D convolution in many ways before, in the time-domain, by FFT, or by FFT with overlap-add, but I have never did that in 2D until now. I tried to but I have a problem that I just cannot solve. The vertical convolution works properly, but the problem with the horizontal convolution is that the last kernel_width-1 bins stay to 0. I'm pretty sure that I have made a d...

Hi Im currently in a bit of muddle. Im currently doing an assignment (in c on TMS320C6713 DSK) and we have been told clearly that we cannot...

Hi Im currently in a bit of muddle. Im currently doing an assignment (in c on TMS320C6713 DSK) and we have been told clearly that we cannot use FFT and we must use Convolution. At this point im reading lots of web sites (TI.Com) etc and i have found a convolution.c example program. However when i read this example they are implementing convolution whilst using FFT functions?? I have...

Hi all, I need to convolve a sine wave with random signal. I made use of the conv function in matlab. I am expecting a dual-dirac histogram for...

Hi all, I need to convolve a sine wave with random signal. I made use of the conv function in matlab. I am expecting a dual-dirac histogram for the resulting convolution. But I keep getting the gaussian histogram of the random signal as the result of the convolution. Can anyone suggest a proper code for performing the convolution between them? Thanks, Nitin

I read the chapter about FFT convolution (chapter 18) on dspguide.com and from what I understood, to perform a FFT convolution, you perform...

I read the chapter about FFT convolution (chapter 18) on dspguide.com and from what I understood, to perform a FFT convolution, you perform a FFT on your filter kernel and on your signal (after you have changed their size and zero padded), you multiply each real and imaginary part of the two signals, and then you perform an IFFT, and with that you're supposed to get the same result as with a ...

Hello. I would like to obtain the convolution of two spectra. I have the complex form Fourier coefficients for the first 300 harmonics of each...

Hello. I would like to obtain the convolution of two spectra. I have the complex form Fourier coefficients for the first 300 harmonics of each spectra. I was looking at the definition of convolution in one of my books and the sumation term goes from -infinity to infinity. Can I obtain a good accurate convolution with the terms i have or do I have to also calculate the terms for the negative...

I'm looking for a simple (need not be very efficient) VC++/C++ library that does the image (png) convolution, 2D FFT. I would like to develop a...

I'm looking for a simple (need not be very efficient) VC++/C++ library that does the image (png) convolution, 2D FFT. I would like to develop a image search feature (http://www.dspguide.com/ch24/6.htm) with a VC+ + based GUI around it. http://www.codeproject.com/KB/graphics/ImageConvolution.aspx does have the convolution feature but not FFT. Anybody gone through the same requirement? Thank...

Hi to all, I've been writing an application in JAVA that uses the Fourier Transform, and performs several operations, such as the...

Hi to all, I've been writing an application in JAVA that uses the Fourier Transform, and performs several operations, such as the convolution. The convolution is being processed in the time domain, so when signals lenths are big (i.e. 1000 values or more), it takes very long to process the convolution. So the best way to do this is by working in the frequency domain. Does anybody know ...

Hi, all, I am new to DSP. I try to verify the convolution in time domain equal to the mulitplication in freq domain. I have a input signal of...

Hi, all, I am new to DSP. I try to verify the convolution in time domain equal to the mulitplication in freq domain. I have a input signal of 128 points and a filter of 30 points. I do FFT of the input signal and filter(pad zero). end up with 128 points of both signal in freq domain. I then do multiplication of the two. In time domain, I do convolution of the input signal and the filter, which en...

Hi, I have created a three flash program that demonstrate: Discrete convolution Low Pass FIR filters Band Pass FIR filters. It is...

Hi, I have created a three flash program that demonstrate: Discrete convolution Low Pass FIR filters Band Pass FIR filters. It is located here: http://www.fourier-series.com/fourierseries2/convolution.html Brent

Hi, I am new to this programming world, and i really need some serious help. I have done a program in which i design a filter in frequency...

Hi, I am new to this programming world, and i really need some serious help. I have done a program in which i design a filter in frequency domain, then i take a CT image, which is a 3d image, read each voxel and make a 1d array. then i equal the number of samples for both the data set. so i have equal samples. then i do convolution using fftw3 library. but what happens is that i am doing circula...

hello everybody!! can anyone tell me in calculating circular convolution using DFT what will happen if i use two different length...

hello everybody!! can anyone tell me in calculating circular convolution using DFT what will happen if i use two different length signal? suppose one is of 4 point and the other is of 3 point then what will be the system?i have to do both 4 point DFT?or 4+3-1 or 6 point DFT as like linear convolution... plz help me out.. shatila

It seems to me that cepstral mean subtraction (CMS), which is commonly performed in computer speech recognition system, corresponds to...

It seems to me that cepstral mean subtraction (CMS), which is commonly performed in computer speech recognition system, corresponds to a circular convolution. I am curious what people think about how I'm viewing this and about the possible effects of changing CMS to use a linear convolution. This post turned out very long, so if you're in a hurry please just read from the fourth paragraph...