i'm trying to implement a real-time partitioned/fast convolution and having real trouble getting my head around which partitions to multiply...

i'm trying to implement a real-time partitioned/fast convolution and having real trouble getting my head around which partitions to multiply with which, and what to cumulatively sum and output etc... can anyone offer or link to some pseudocode explaining it step by step or a diagram? thanks.

I have a set of $M$ infinite data sequences, and I hope to perform a series of convolutions such that SEQ_result = SEQ_1 * SEQ_2 * SEQ_3 * ......

I have a set of $M$ infinite data sequences, and I hope to perform a series of convolutions such that SEQ_result = SEQ_1 * SEQ_2 * SEQ_3 * ... SEQ_M I am only interested at the first few terms of SEQ_result. Right now, I can only think of one method, which is to use fast convolution (truncation all to finite sequences, FFT, pointwise multiply, iFFT). Is there other efficient way to imple...

If y = conv(x,w) What is the derivative of y with respect to w ? Here y is the convolution between x and w, all are one dimensional....

If y = conv(x,w) What is the derivative of y with respect to w ? Here y is the convolution between x and w, all are one dimensional. Thanks This message was sent using the Comp.DSP web interface on www.DSPRelated.com

Hello, I am thinking about a question about how to figure out whether a linear filter really filters out anything against a particular...

Hello, I am thinking about a question about how to figure out whether a linear filter really filters out anything against a particular sequence (or any sequence). Here I don't want to compute w/ convolution, but I don't know if it is possible to think in a convolution way for my problem. For example, I might have 2 filters h1 and h2,where h1 = [-1 0 1], h2 = [-1 2 -1] Their magnitude...

Hi, i searched the web for quite some time now and just don't grok how to normalize when doing partitioned frequency domain...

Hi, i searched the web for quite some time now and just don't grok how to normalize when doing partitioned frequency domain convolution. Basically for an unnormalized FFT/IFFT pair (i use fftw, so all the FFT/IFFT i use is unnormalized), the necessary normalization factor would be 1/N applied once or 1/sqrt(N) applied twice. But now i have IFF(FFT(signal)*FFT(response)) and i wonder wh...

Hi I am not totally new to DSP, I did do a module in it at University as part of my Masters, but that was around 15 years ago... I am...

Hi I am not totally new to DSP, I did do a module in it at University as part of my Masters, but that was around 15 years ago... I am looking at implementing audio effects, such as reverberation and amplifier/speaker modelling, by the convolution of an audio signal with an impulse response recorded from a room or amplifier. Specifically I want to implement a bass guitar amp model to improve ...

Hi all, I intuitively had an idea that f(t) ** g(t) = f'(t) ** int(g(t)) = int(f(t)) ** g'(t) where " ' " denotes differentiation,...

Hi all, I intuitively had an idea that f(t) ** g(t) = f'(t) ** int(g(t)) = int(f(t)) ** g'(t) where " ' " denotes differentiation, int(f(t)) denotes integration, " ** " denotes convolution. I want to prove it is true but I met with some difficulties for which I need your help! Let me first define convolution as integral from -infinity to +infinity, if I define int(f(t)) to be ...

Hi all, Suppose the forced input to the system is f(t), the step response of the system is a(t) and the output is y(t). Now we want to find...

Hi all, Suppose the forced input to the system is f(t), the step response of the system is a(t) and the output is y(t). Now we want to find y(t), I am confused: Which of the following is the correct output y(t)? (1) y(t)=convolution(differentiate(a(t)), f(t)) and (2) y(t)=differentiate(convolution(a(t), f(t)) ??? All "differentiate" and "convolve" operations...

Hi all, I have recently implemented a fast convolution algorithm using the FFT/iFFT to convert input signal and filter into the frequency...

Hi all, I have recently implemented a fast convolution algorithm using the FFT/iFFT to convert input signal and filter into the frequency domain, multiply them out, and iFFT them back to the time domain to get my result. It all seems to work fine, however, I recently got a little confused on one point. I need to determine the gain that my filter will be applying to the signal. I've done thi...

I've made an overlap-add/FFT convolution function, the problem with it is that it mostly outputs samples which value is infinite. I isolated the...

I've made an overlap-add/FFT convolution function, the problem with it is that it mostly outputs samples which value is infinite. I isolated the problem in the function and it appears to be at the level of my complex multiplication context : i have cut the long input signal into nblocks and put each part into an array block[], i of course zeropadded each block, then FFTed each block, and h...

Hi, Does anybody have the fastest method (using paper and pencil) to calculate the convolution: y[n]=x[n]*h[n] where x[n]=u[n-3] -...

Hi, Does anybody have the fastest method (using paper and pencil) to calculate the convolution: y[n]=x[n]*h[n] where x[n]=u[n-3] - u[n-14], h[n]=u[n-5] - u[n-8], where u[n] is the step function, u[n]=1 for n> =0, and u[n]=0 for n

Hi, I am starting to learn DSP. I have one fundemental question. I understood the sampling process if the input signal(Fin) is a sinewave...

Hi, I am starting to learn DSP. I have one fundemental question. I understood the sampling process if the input signal(Fin) is a sinewave and an impulse train is used as a clock(Fclk), it is mulitplication in time domain, which is convolution in frequency domain. The input signal is preserved becuase of the convolution with the clock signal at DC. (Fin+/-N*Fclk when N=0 we still have F...

Dear All, I would like to convolve two complex sequences. Could anybody help me how to define the convolution of two complex sequences...

Dear All, I would like to convolve two complex sequences. Could anybody help me how to define the convolution of two complex sequences please? Thanks in advanced. Regard, nmaedewi This message was sent using the Comp.DSP web interface on www.DSPRelated.com

Dear All, I would like to convolve two complex sequences. Could anybody help me how to define the convolution of two complex sequences...

Dear All, I would like to convolve two complex sequences. Could anybody help me how to define the convolution of two complex sequences please? Thanks in advanced. Regard, estdev

Hi - I'm interested in computing 2d convolutions of matrix X with arbitrary kernel K and its non-conjugate transpose K'. Is there a way to...

Hi - I'm interested in computing 2d convolutions of matrix X with arbitrary kernel K and its non-conjugate transpose K'. Is there a way to compute conv2(X,K) and conv2(X,K') faster than doing 2 generic convolutions? Also, if kernel KK has radial symmetry, can conv2(X,KK) be computed faster than doing a generic convolution? Thanks!

Does anyone know where I might obtain a Matlab function to perform a fast convolution in Matlab. I have my own but its written in Matlab. I'd...

Does anyone know where I might obtain a Matlab function to perform a fast convolution in Matlab. I have my own but its written in Matlab. I'd like one that was done in C(++), fortran, ect. Speed is an issue. S.M.

Hi everyone, I'm trying to implement a digital filter in c++ (assignment work, so I can't just use one that someone else has written...

Hi everyone, I'm trying to implement a digital filter in c++ (assignment work, so I can't just use one that someone else has written (--bummer)) and along the way I've discovered that my knowledge of (low pass) filtering isn't quite what it should be. I designed my filtering algorithm around convolution of two sequences, but when testing in Matlab I've come across an issue. %example code...

I recently implemented fast convolution filtering for the "tools" portion of KISS FFT ( http://sourceforge.net/projects/kissfft ) I've seen a...

I recently implemented fast convolution filtering for the "tools" portion of KISS FFT ( http://sourceforge.net/projects/kissfft ) I've seen a few realizations of the overlap-scrap (aka overlap save) method. They all have the scrapped output samples at the beginning of the output buffer. Those realizations require an additional buffer copy to write continuous output. I found a way to...

hi to everyone, I need to find WORKING dsp routines, that is, not vague or damned crypted or totaly wrong routines ( usually these are find...

hi to everyone, I need to find WORKING dsp routines, that is, not vague or damned crypted or totaly wrong routines ( usually these are find in most books). By the way , I want implement a simple ( for you,not for me) procedure to do FFT convolution of large signals ,so I think I must windowing segments of the signal , to make the convolution and to use some type of overlap in order to ...

Hello! I have been trying to implement an image in image search algorithm using fft, as described in the dspguide, chapter 24...

Hello! I have been trying to implement an image in image search algorithm using fft, as described in the dspguide, chapter 24 (http://www.dspguide.com/), using FFT Convolution. As far as I have understood it, the search image is used as some kind of a filter (like sharpen, etc.) on the original image (in which I search) in order to give the resulting image a distribution of similarity of...