hi Hidden Markov Model anyone

Started by senthil mani in Matlab DSP19 years ago

hi, Has anyone here worked on Hidden Markov Models. I am implementing an automatic speech recognition system(identifing ...

hi, Has anyone here worked on Hidden Markov Models. I am implementing an automatic speech recognition system(identifing words 1 to 5) using wavelet analysis(in Matlab) and I have completed the feature extraction stage now the problem is identifing the word( one to


wavelets (windowing)

Started by matchbox2070 in Matlab DSP18 years ago

I would like to ask the people who have experiences in wavelets. I am doing frame by frame wavelet packet decomposition , im...

I would like to ask the people who have experiences in wavelets. I am doing frame by frame wavelet packet decomposition , im just wondering whether overlap windowing should be done like that in taking frame by frame fourier transform ( does it apply to fram by frame wav


time-frequency distribution

Started by John in Matlab DSP20 years ago

How to present time-frequency distribution using wavelet transformation or reassigned Gabor transformation? Many Thanks. ...

How to present time-frequency distribution using wavelet transformation or reassigned Gabor transformation? Many Thanks.


how to get spectrogram like plot using wavelets

Started by calmncool82 in Matlab DSP14 years ago

Hi everyone, i did short time fourier transform(STFT) on 1-D speech signals, and did spectrogram analysis. On one paper I found that it is...

Hi everyone, i did short time fourier transform(STFT) on 1-D speech signals, and did spectrogram analysis. On one paper I found that it is possible to come up with a wavelet based analogy of spectrograms, it was called "scalogram" at that paper. So, I set about trying to figure out a way to come up with scalogram code in matlab. After coding a matlab program which does a full decomposition...


MAT files conversion

Started by junejonoman in Matlab DSP18 years ago 1 reply

Dear All Does anyone know how to convert a .MAT file into an image file The basic problem is that I am using the wavelet toolbox...

Dear All Does anyone know how to convert a .MAT file into an image file The basic problem is that I am using the wavelet toolbox which saves the image compression results in a Mat file so I need to convert it into some standard form to see the result another does anyone


Wavelet compression

Started by Pavel Havranek in Matlab DSP20 years ago

Hi all, I work with MATLAB R11 on image compression by wavelets. I need compress ratio about 150 to 1 but MATLAB has worse result...

Hi all, I work with MATLAB R11 on image compression by wavelets. I need compress ratio about 150 to 1 but MATLAB has worse result after compresion as commercial product (LuraTech). I need compress image 176x176 to 256 numbers (char) but I don't know which coeficient I must save. I ca


Wavelet based OFDM

Started by Oswald Jumira in Matlab DSP13 years ago

Has anyone worked with wavelets based OFDm. I would like to know how one included the idwt and dwt fucntion for an OFDM code. --...

Has anyone worked with wavelets based OFDm. I would like to know how one included the idwt and dwt fucntion for an OFDM code. -- Regards Oswald Jumira Communications Research Group Room 5.26 Menzies Building Department of Electrical Engineering University of Cape Town P Bag X5 Rondebosch 7701 Tel: +27216504879 Cel: +27720308211 Email: o...@uct.ac.za o...@ieee.org "To raise new...


filterbanks problem?

Started by omid...@yahoo.com in Matlab DSP15 years ago

This MATLAB program is for making a suitable wavelet kernel It derives the Low pass filter by sampling from analog raised cosine function in...

This MATLAB program is for making a suitable wavelet kernel It derives the Low pass filter by sampling from analog raised cosine function in frequency domain and taking ifft from this function to yield the impulse response. (other filters are derived using orthogonal relations). first i wnat know if the filter design method has any problems? The filter has 2 parameters in frequency domain ...


how to capture voice in matlab at 16000 samples/sec

Started by salman6301 in Matlab DSP17 years ago

i want to capture my voice in matlab .and then i want to sample it at 16000 samples/sec.then i want to take its FFT and...

i want to capture my voice in matlab .and then i want to sample it at 16000 samples/sec.then i want to take its FFT and wavelet transform.plz i want immediate help salman


Tree vector

Started by vani chezhiyan in Matlab DSP17 years ago

Hi all, I have a doubt in constructing a tree vector. I have a signal for which i took wavelet transform.i have got the...

Hi all, I have a doubt in constructing a tree vector. I have a signal for which i took wavelet transform.i have got the approximation and detail coefficients ,how will i construct a tree vector for these coefficients.I have decomposed the signal to five levels.can anyone please help m


Problems using wavread function for audiowatermarking project

Started by Ambika Menon in Matlab DSP12 years ago

Hi, I am doing a project on audio watermarking using Matlab. I am facing the following problem. I took a small subset of the samples of a...

Hi, I am doing a project on audio watermarking using Matlab. I am facing the following problem. I took a small subset of the samples of a .wav file. I embedded a small bitmap in the LSBs of the wavelet coefficients of this small set of samples and recreated a new .wav file. I wrote the file with the wavwrite function. As the next step, in order to detect the watermark, I read the wa...


Any chance of using chirp-Z within STFT (specgram or alike)

Started by Alex Z in Matlab DSP15 years ago

I intend to analyze a non-stationary audio signal for its spectral content after splitting it up by several narrow frequency...

I intend to analyze a non-stationary audio signal for its spectral content after splitting it up by several narrow frequency bands (sub-bands). Splitting is performed by wavelet decomposition at required level, then I thought of running an STFT (specgram with narrow window) within each band to figure its spectrum content. Since the bands are quite narrow (several hundreds of herz each) ther...


Error using waverec when dwtmode set to 'per'

Started by MAST...@UWALUMNI.COM in Matlab DSP15 years ago

Hello, I have a question regarding the wavelet decomposition and reconstruction using the functions wavedec and waverec. I get an error during...

Hello, I have a question regarding the wavelet decomposition and reconstruction using the functions wavedec and waverec. I get an error during the reconstruction process when I set the dwtmode option to 'per'. The code I use is as follows: ----------------------------------- dwtmode('per') x = random('unif', 0, 1, 512, 1); [y, L] = wavedec(x, 9, 'db2'); x_rec = waverec(y, L, 'db2'); ---...


how can i takt wavelet transform from an image and then inverse(transform) it ?

Started by ali_khodaie2002 in Matlab DSP12 years ago 1 reply

hi my dear freinds around the world, i wanted to transform(dwt) an image(barbara)and inverse it.it is my first time i have worked with dwt.these...

hi my dear freinds around the world, i wanted to transform(dwt) an image(barbara)and inverse it.it is my first time i have worked with dwt.these are my codes: X=((imread('barbara.bmp'))); [cA,cH,cV,cD] = dwt2(X,'haar'); Y = idwt2(cA,cH,cV,cD,'haar'); figure,imshow(Y) but the resulting image isn`t like the first image . what `s wrong with my codes? thanks in advance.


Watermarking- losing color component..plz help

Started by p_r_a_d53 in Matlab DSP13 years ago

I m working on the project "wavelet based watermarking". am using the dwt2 function to get the approximation parameter. while doing so.. Iam...

I m working on the project "wavelet based watermarking". am using the dwt2 function to get the approximation parameter. while doing so.. Iam losing the color of the watermarked image. plzz help me out in obtaining the color component Here is my code.. a=imread('H:\pics\earth_from_space.jpg'); %i=imread('earth_from_space.jpg'); %i=uigetfile( '*.*' , 'select the image'); %[filename1,pat...