Thread Subject:

reconstruction

Hi all...

How to reconstruct 2D image for Electrical Capacitance Tomography (ECT) system if I have matrix G with 1024 x 1 dimension (G is the permittivity image)?

Thanks

Asep

I have been reshape Matrix G to 32 x 32 dimension, how to reconstruct 2D image?

Thanks

"Asep " <rachmatlipi@yahoo.com> wrote in message <jqugn5$6nc$1@newscl01ah.mathworks.com>...
> Hi all...
>
> How to reconstruct 2D image for Electrical Capacitance Tomography (ECT) system if I have matrix G with 1024 x 1 dimension (G is the permittivity image)?
>
> Thanks
>
> Asep

"Asep " <rachmatlipi@yahoo.com> wrote in message <jqusln$lnp$1@newscl01ah.mathworks.com>...
> I have been reshape Matrix G to 32 x 32 dimension, how to reconstruct 2D image?
>

If you have G already, what is there to reconstruct?

G is grey level image, and i want to reconstruct G.

Thanks Matt

"Matt J" wrote in message <jqv86b$534$1@newscl01ah.mathworks.com>...
> "Asep " <rachmatlipi@yahoo.com> wrote in message <jqusln$lnp$1@newscl01ah.mathworks.com>...
> > I have been reshape Matrix G to 32 x 32 dimension, how to reconstruct 2D image?
> >
>
> If you have G already, what is there to reconstruct?

"Asep " <rachmatlipi@yahoo.com> wrote in message <jr46o3$12c$1@newscl01ah.mathworks.com>...
>
>
> G is grey level image, and i want to reconstruct G.

But you said you already have G. If you don't have G, what do you have? And what algorithm were you hoping to use? And what portion of the code for this algorithm have you created already?

Yes, I have G already. I have got G with linear back projection algorithm and my code that I created only until I get my G. The problem is how to reconstruct the image of G and what kind of code that I can use.

Thanks a lot Matt

Regards,
Asep

"Matt J" wrote in message <jr4hkr$bof$1@newscl01ah.mathworks.com>...
> "Asep " <rachmatlipi@yahoo.com> wrote in message <jr46o3$12c$1@newscl01ah.mathworks.com>...
> >
> >
> > G is grey level image, and i want to reconstruct G.
>
> But you said you already have G. If you don't have G, what do you have? And what algorithm were you hoping to use? And what portion of the code for this algorithm have you created already?

On 6/11/2012 7:14 AM, Asep wrote:

> Yes, I have G already. I have got G with linear back projection algorithm
>and my code that I created only until I get my G. The problem is how
>to reconstruct the image of G and what kind of code that I can use.
>


But you have the image G you say. You already constructed it using
your algorithm.

So, not sure what does this mean:

"The problem is how to reconstruct the image of G"

May be it helps to explain your problem from the start:

Explain what is the input, and what is the output.

every engineering problem has an input and an output.

in the exam, the teacher always wants us to write at
the top of the solution the following:

GIVEN:
FIND:
ASSUMPTIONS:

they take 10% of the grade if we do not do this for each problem.

May be you can do the same for this problem?

(and better not to not TOP POST as it messes up the flow)

>
> "Matt J" wrote in message<jr4hkr$bof$1@newscl01ah.mathworks.com>...
>> "Asep "<rachmatlipi@yahoo.com> wrote in message<jr46o3$12c$1@newscl01ah.mathworks.com>...
>>>
>>>
>>> G is grey level image, and i want to reconstruct G.
>>
>> But you said you already have G. If you don't have G, what do you have?
> And what algorithm were you hoping to use? And what portion of the code for this
>algorithm have you created already?

--Nasser

Dear Matt.
My code/script to get G is:

clear all
clear C0 G0 delta_C delta_G G1 Gk alpha St

A=load ('cmeas.txt','ascii');
B=load ('cfull.txt','ascii');
D=load ('cempty.txt','ascii');

load ('MSDAT','-mat');
C0 = ((A-D)./(B-D));

normcap = C0(1:120,1);
ncp(1,1:120) = C0;
iter = 5;
alpha0 = 3.5;
t = 0;
St = MS';
G0 = St * a;
eval = 1;
t1 = 1;
serr = 0;

    while t1 <= iter
        delta_C = C0 -(MS * G0);
        G = G0 + alpha0 * (St * delta_C);
        err = abs(G - G0);
        serr = serr + sum(err.^2);
        G(find(G>1))=1;
        G(find(G<0))=0;
        G0 = G;
        t1 = t1 + 1;
    end
    
nx = 32;
ny = 32;


image1 = reshape(G,nx,ny);

==========================================
and then what should I do to reconstruct my G or my image1?


regards,

Asep


"Asep " <rachmatlipi@yahoo.com> wrote in message <jr4nef$50p$1@newscl01ah.mathworks.com>...
> Yes, I have G already. I have got G with linear back projection algorithm and my code that I created only until I get my G. The problem is how to reconstruct the image of G and what kind of code that I can use.
>
> Thanks a lot Matt
>
> Regards,
> Asep
>
> "Matt J" wrote in message <jr4hkr$bof$1@newscl01ah.mathworks.com>...
> > "Asep " <rachmatlipi@yahoo.com> wrote in message <jr46o3$12c$1@newscl01ah.mathworks.com>...
> > >
> > >
> > > G is grey level image, and i want to reconstruct G.
> >
> > But you said you already have G. If you don't have G, what do you have? And what algorithm were you hoping to use? And what portion of the code for this algorithm have you created already?

"Asep " <rachmatlipi@yahoo.com> wrote in message <jr4ov7$bjk$1@newscl01ah.mathworks.com>...
> Dear Matt.
> My code/script to get G is:
>
> clear all
> clear C0 G0 delta_C delta_G G1 Gk alpha St
>
> A=load ('cmeas.txt','ascii');
> B=load ('cfull.txt','ascii');
> D=load ('cempty.txt','ascii');
>
> load ('MSDAT','-mat');
> C0 = ((A-D)./(B-D));
>
> normcap = C0(1:120,1);
> ncp(1,1:120) = C0;
> iter = 5;
> alpha0 = 3.5;
> t = 0;
> St = MS';
> G0 = St * a;
> eval = 1;
> t1 = 1;
> serr = 0;
>
> while t1 <= iter
> delta_C = C0 -(MS * G0);
> G = G0 + alpha0 * (St * delta_C);
> err = abs(G - G0);
> serr = serr + sum(err.^2);
> G(find(G>1))=1;
> G(find(G<0))=0;
> G0 = G;
> t1 = t1 + 1;
> end
>
> nx = 32;
> ny = 32;
>
>
> image1 = reshape(G,nx,ny);
>
> ==========================================
> and then what should I do to reconstruct my G or my image1?
>
>
> regards,
>
> Asep
>
>
> "Asep " <rachmatlipi@yahoo.com> wrote in message <jr4nef$50p$1@newscl01ah.mathworks.com>...
> > Yes, I have G already. I have got G with linear back projection algorithm and my code that I created only until I get my G. The problem is how to reconstruct the image of G and what kind of code that I can use.
> >
> > Thanks a lot Matt
> >
> > Regards,
> > Asep
> >
> > "Matt J" wrote in message <jr4hkr$bof$1@newscl01ah.mathworks.com>...
> > > "Asep " <rachmatlipi@yahoo.com> wrote in message <jr46o3$12c$1@newscl01ah.mathworks.com>...
> > > >
> > > >
> > > > G is grey level image, and i want to reconstruct G.
> > >
> > > But you said you already have G. If you don't have G, what do you have? And what algorithm were you hoping to use? And what portion of the code for this algorithm have you created already?


Dear Nasser,

Thanks for your kind advice and I apologize if my post located in the top of message.

Yes you right, i have been found G with matlab script above, but still in grey level image. How to convert that image to RGB level.

Thanks

Asep