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Ahmed Ragab
Joined: 30 Jun 2004
Posts: 350
Helped: 118
Location: Egypt
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 11 Oct 2004 0:41 Discrete cosine transform .. help!! |
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Any one has any pdf's on the discrete cosine transform?
i need to get data about the definition, basis function, inverse , fast algorithms
Thanks for all.
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ramesh
Joined: 19 Jan 2003
Posts: 1260
Helped: 5
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11 Oct 2004 3:23 Re: Discrete cosine transform .. help!! |
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| Refer any book on Digital Image Processing. You will find many transform coding techniques including Discrete Cosine transform for image compression. You may also search the forum for Digital Image Processing by Pratt.
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me2please
Joined: 07 Aug 2004
Posts: 362
Helped: 64
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cedance
Joined: 24 Oct 2003
Posts: 704
Helped: 28
Location: Germany
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11 Oct 2004 5:22 Re: Discrete cosine transform .. help!! |
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| Ahmed Ragab wrote: |
Any one has any pdf's on the discrete cosine transform?
i need to get data about the definition, basis function, inverse , fast algorithms
Thanks for all. |
reg. the boks there are plenty availkable here itself...
http://www.edaboard.com/viewtopic.php?t=63137&highlight=dct
http://www.edaboard.com/viewtopic.php?t=89708&highlight=dct
and many moire...
/cedance
Last edited by cedance on 12 Mar 2005 13:59; edited 1 time in total |
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Google
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11 Oct 2004 5:22 Ads |
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omara007
Joined: 06 Jan 2003
Posts: 1283
Helped: 39
Location: Dubai
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11 Oct 2004 13:24 Re: Discrete cosine transform .. help!! |
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Salam Ahmed ..
On Opencores.org u'll find a complete DCT project made by Sherif Taher .. it includes both docs and source codes ..
Just enjoy 
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kunal
Joined: 27 Jun 2004
Posts: 18
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13 Oct 2004 19:05 Re: Discrete cosine transform .. help!! |
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you can also refer to the JPEG and MPEG standards as the basis of these compression is DCT only. These groups maintain their own sites and u can easily find them by searching thru google
regards,
kunal
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weixiang
Joined: 11 Oct 2004
Posts: 7
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25 Oct 2004 1:13 Discrete cosine transform .. help!! |
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| DCT is getting out of phase. DWT is getting its way into digital image and video processing such as JPEG-2000, H.264, etc.
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DrDolittle
Joined: 24 Sep 2004
Posts: 169
Helped: 4
Location: Within arm's reach
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25 Oct 2004 8:48 Re: Discrete cosine transform .. help!! |
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The professor under whom Iam working has done a paper which is a reconfigurable architecture in which all known transforms are done in terms of DCT and DST..If you find that this could help you i can upload that paper.
Regards
drdolittle
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dora
Joined: 11 Jun 2003
Posts: 158
Helped: 2
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25 Oct 2004 8:58 Re: Discrete cosine transform .. help!! |
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Yes DrDolittle I think this article will be interesting .
Best Regards
dora
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abhigopal
Joined: 21 Dec 2004
Posts: 62
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24 Dec 2004 21:30 Re: Discrete cosine transform .. help!! |
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maybe this would help
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spweda
Joined: 28 Jun 2001
Posts: 195
Helped: 4
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25 Dec 2004 0:01 Re: Discrete cosine transform .. help!! |
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| Rao(from U. Texas Ausdin) wrote a book on fast discret cosine tranform and its application. It was published about 15 years ago. You oculd find it in the local university library.
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me2please
Joined: 07 Aug 2004
Posts: 362
Helped: 64
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25 Dec 2004 7:13 Discrete cosine transform .. help!! |
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| K. R. Rao is with U of Texas at Arlington, not Austin. He discovered the DCT with N. Ahmed (now with UNM).
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husam_sdu
Joined: 26 Dec 2004
Posts: 2
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26 Dec 2004 21:15 Re: Discrete time dsp in matlab... help!! |
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eg. i have x(n)={...,0,0,1,2,1,-1,0,0...} i want to fft this signal when N=4,8,16
[X(k)=?] in matlab.and i couldn't.would you mind helping me quickly? thanks:)
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abhigopal
Joined: 21 Dec 2004
Posts: 62
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26 Dec 2004 21:53 Discrete cosine transform .. help!! |
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I am guessing you use the function fft(x,n) where n is 4,8,.. and x is the array u define..
FFT(X,N) is the N-point FFT, padded with zeros if X has less
than N points and truncated if it has more.
hope this helps
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boeysue
Joined: 23 Dec 2004
Posts: 190
Helped: 3
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03 Jan 2005 16:28 Re: Discrete cosine transform .. help!! |
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fftw project on the internet maybe can help you.
It is a project of the group of fft .
Maybe it will have the DCT.
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dianacgil
Joined: 23 Aug 2004
Posts: 13
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20 Jan 2005 7:43 Re: Discrete cosine transform .. help!! |
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Some DCT/IDCT papers...
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mehello
Joined: 15 Apr 2003
Posts: 13
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21 Jun 2005 10:14 Discrete cosine transform .. help!! |
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| also looking for good IDCT/DCT papers ,
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dianacgil
Joined: 23 Aug 2004
Posts: 13
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26 Jul 2005 0:19 Re: Discrete cosine transform .. help!! |
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"Good papers"... That depends on what you are doing, if you are just studying, exploring new methods or implementing it in a specific platform...
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vadkudr
Joined: 12 Jul 2005
Posts: 120
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26 Jul 2005 1:02 Re: Discrete cosine transform .. help!! |
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Great work on unified algebraic framework for discrete trigonometric transforms
and for fast algorithms for them
This theory allows even automatic optimization of fast algorithms
http://www.ece.cmu.edu/~pueschel/papers/dttalgo.pdf
And for DrDolittle -> please send me the paper of your professor
E-Mail : vadkudr(at)tut.by
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swahlah
Joined: 24 Mar 2005
Posts: 145
Helped: 16
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26 Jul 2005 6:01 Re: Discrete cosine transform .. help!! |
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The best way to learn about Discrete Transform is to read any book of Image Processing.
If you want to learn how DCT is used specifically in image compression then the best thing to start with is JPEG standard
You can be in touch with jpeg on
http://www.edaboard.com/viewtopic.php?t=125843&sid=946aac849d559fc045cfe650bdcf7dca
In addition H.264 has new 4x4 integer transform which is basically derived from actual DCT.
There are lots of fast DCT algorithms and you can easily search fast DCT algorithms on google.
I will look into my repository if i get something for you
-Regards
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lijun
Joined: 26 Jul 2005
Posts: 3
Helped: 1
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27 Jul 2005 15:42 Re: Discrete cosine transform .. help!! |
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I have done a lot of DCT fast implementation and test, including DCT8x8, DCT4x4, DCT248. Please check the attached source code. Hope it is helpful
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eelxl
Joined: 27 Jul 2005
Posts: 5
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28 Jul 2005 16:42 Re: Discrete cosine transform .. help!! |
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Good paper for DCT
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eelxl
Joined: 27 Jul 2005
Posts: 5
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28 Jul 2005 16:43 Re: Discrete cosine transform .. help!! |
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Another good paper
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ankit12345
Joined: 27 Dec 2005
Posts: 292
Helped: 6
Location: bangalore,India
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04 Feb 2006 13:28 Discrete cosine transform .. help!! |
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| You can get the code from www.opencores.org
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ys82
Joined: 25 Feb 2008
Posts: 14
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08 Jan 2009 10:08 Re: Discrete cosine transform .. help!! |
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| eelxl wrote: |
| Good paper for DCT |
Thanks a lot
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