Re: Re: [WM]: Watermarking using Modified Trellis

["Frank Ling" <lhefei@163.com>]

Dear Madan,

=A1=A1=A1=A1I am a PH.D student of Huazhong University of Science and =
Technology in China. My research focuses on Video watermarking. Now I
have encountered a challenged problem that how to resist global and =
local geometrical distortion while keep the algorithm's
real-time property.

I am glad to make a more  discussion with you!

Yours sincerely,
Frank Ling
=20



HI Frank Ling,

Thank you very much......Wat do you do?
I'm in doing my final year in electronics and communication engineering =
in India. Like to know abt u.

with regards,
Madan mohan

Frank Ling <lhefei@163.com> wrote:
Hello, madan mohan

I have implemented this method, but i found the idea that each arch is =
generated randomly is not good. An elaborate trellis
structure is better. the fowllowing code maybe help you.

function [isok,trellis] =3D createTrellis(key,InputK, InputM, OutputN)

% key =3D 1234;
%
% InputK =3D 2;
% OutputN=3D12;
% InputM=3D2;

numInputSymbols =3D 2^InputK;
numStates =3D 2^InputM;
numOutputSymbols =3D 2^OutputN;

% seed =3D randseed(key);
Keys =3D randseed(key,numStates);
Keys =3D Keys';
% Keys =3D randint(numStates,1,[0,2147483647]);


for i =3D 1:numStates
NextStateEven(i,:) =3D mod((i-1),2):2:(numInputSymbols-1); %represent 0
NextStateOdd(i,:) =3D mod(i,2):2:(numInputSymbols-1); %represent 1=20
NextState(i,1:2:numInputSymbols) =3D NextStateEven(i,:);
NextState(i,2:2:numInputSymbols) =3D NextStateOdd(i,:); end

% compute how many outlets for each state

numOutputPerS =3D numInputSymbols;

CycleNum =3D (InputM + InputK)/(OutputN - InputM - InputK);

for i =3D 1:numStates
rand('state',Keys(i));
tmp =3D randint(numOutputPerS,OutputN);

TempDec(1:numOutputPerS) =3D 0;
nn =3D size(tmp,2);
for kk =3D 1:nn
TempDec(:) =3D TempDec(:)*2 + tmp(:,kk);
end


TmpOct =3D base2dec(dec2base(TempDec,8),10);

NextOutput(i,:) =3D TmpOct';
end

trellis =3D =
struct('numInputSymbols',numInputSymbols,'numOutputSymbols',numOutputSymb=
ols,...
'numStates',numStates,'nextStates',NextState,...
'outputs',NextOutput);

[isok,status] =3D istrellis(trellis);


Frank Ling



=3D=3D=3D=3D=3D=3D=3D 2005-01-19 14:31:55 =3D=3D=3D=3D=3D=3D=3D

>Hi,
>=20
>I'm doing my project ba14:31:55 =3D=3D=3D=3D=3D=3D=3D

>Hi,
>sed on IEEE paper "Applying informed coding and=20
>embedd on IEEE paper "Applying informed coding and=20
>ing to design a robust high capacity watermark by M.L.Miller, Gwenael =
J.Doerr and I.J.Cox.
>I have doubt in makin, Gwenael J.Doerr and I.J.Cox.
>g a modified trellis structure for encoding process described in the =
paper. I would like to implement it
>matlab. Can any one help me in the process of implementing in matlab?=20
>=20
>thank you in advance,
>=20
>Madan


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