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Hello,
I'm very new to this wavelet field..
Can anybody tell how the convolution is done in wavelets ..
B'coz in matlab there is a direct in built function thr'o which u
can achieve Wavelet transform...
But in 'C' v need to write the logic..
Moreover i referred to Numerical recipes in 'C', where he's
given the logic for daubechies(db4)coeffecients...)But the problem is the
coeffecients which is given in the book is not tallying the matlab db4
coeffecients ..I'm totally confused.
Can anybody give me the proper logic ...
Thanx in advance,
Sowmya
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Wavelet doubt
Started by ●June 11, 2002
Reply by ●June 11, 20022002-06-11
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On Tue, 11 Jun 2002, sowmya wrote: > B'coz in matlab there is a direct in built function thr'o which u can achieve Wavelet transform... > > But in 'C' v need to write the logic.. > > Moreover i referred to Numerical recipes in 'C', where he's given the > logic for daubechies(db4)coeffecients...)But the problem is the > coeffecients which is given in the book is not tallying the matlab db4 > coeffecients ..I'm totally confused. I guess it's a little confusion from matlab. In fact, matlab calls the daubechies 4, but in fact it's the daubechies length 8 transform, which has 4 vanishing moments. I've just finished an implementation of this daubechies lenth 8 in C (from the description of the numerical recipes) if you like... -- Kind regards, Filip Rooms Ghent University Department for Telecommunication and Information Processing (TELIN) Sint-Pietersnieuwstraat 41, B-9000, Gent, Belgium ++32 (0)9/264 34 15 http://telin.rug.ac.be/~frooms/ "Don't let your mind wander -- it's too little to be let out alone." |
Reply by ●June 12, 20022002-06-12
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hello sir, Nice to see the reply.. What r this vanishing moments.Can u elucidate it ??If u could send me the copy of that length 8.'C' pgm....i'll be thankful... One more doubt i have that is as i'm applying SPIHT algorithm i want the whole image pixels in the form of matrix of the given size ..I don't know how to extract pixel values in 'C' (that to tiff format).If u have any idea pls let me know.... When v consider .bin format ,u can directly open the .bin file & fscan the pixel values .I tried to do the same thing with tiff but the pixel values which i got r not matching with the pixel values obtained in matlab..So i'm little confused.. Moreover in 'c' when i tried to give lena image of 512x512(lena.bin),its saying array size is too big ...If this is the case then how to handle big images???? Anticipating ur reply, Thanx in advance.. sowmya ----- Original Message ----- From: Filip Rooms <> To: sowmya <> Cc: <> Sent: Tuesday, June 11, 2002 7:15 PM Subject: Re: [imagedsp] Wavelet doubt > On Tue, 11 Jun 2002, sowmya wrote: > > > B'coz in matlab there is a direct in built function thr'o which u can achieve Wavelet transform... > > > > But in 'C' v need to write the logic.. > > > > Moreover i referred to Numerical recipes in 'C', where he's given the > > logic for daubechies(db4)coeffecients...)But the problem is the > > coeffecients which is given in the book is not tallying the matlab db4 > > coeffecients ..I'm totally confused. > > I guess it's a little confusion from matlab. In fact, matlab calls the > daubechies 4, but in fact it's the daubechies length 8 transform, which > has 4 vanishing moments. > > I've just finished an implementation of this daubechies lenth 8 in C > (from the description of the numerical recipes) if you like... > > -- > Kind regards, > > Filip Rooms > > Ghent University > Department for Telecommunication and Information Processing (TELIN) > Sint-Pietersnieuwstraat 41, B-9000, Gent, Belgium > ++32 (0)9/264 34 15 > > http://telin.rug.ac.be/~frooms/ > > "Don't let your mind wander -- it's too little to be let out alone." > |
