Thread Subject: Image Reconstruction from Sinogram - iradon transform

Hi,

I need to reconstruct this sinogram http://yfrog.com/58sinobp using matlab. I've tried using iradon, but nothing meaningful has come out. Could someone help me?

Thanks in advance,
Alper

"Alper Ozturk" <alperozturk83@yahoo.com> wrote in message <hdnjmp$li0$1@fred.mathworks.com>...
> Hi,
>
> I need to reconstruct this sinogram http://yfrog.com/58sinobp using matlab. I've tried using iradon, but nothing meaningful has come out. Could someone help me?
===================

You might try flipping the resulting image upside down. I get a picture of a clown when I do.

"Matt " <xys@whatever.com> wrote in message <hdno7n$pcm$1@fred.mathworks.com>...
> "Alper Ozturk" <alperozturk83@yahoo.com> wrote in message <hdnjmp$li0$1@fred.mathworks.com>...
> > Hi,
> >
> > I need to reconstruct this sinogram http://yfrog.com/58sinobp using matlab. I've tried using iradon, but nothing meaningful has come out. Could someone help me?
> ===================
>
> You might try flipping the resulting image upside down. I get a picture of a clown when I do.

Thanks for the reply...
My try was:

I=imread('sino.bmp');
IR=iradon(I,360);

Since I am completely new to matlab, don't know what's wrong... Flipping does not work, also...

"Alper Ozturk" <alperozturk83@yahoo.com> wrote in message <hdoks1$rbg$1@fred.mathworks.com>...

> IR=iradon(I,360);

Read the help doumentaiton on iradon again.
The above is telling iradon() that there is a 360 degree angular increment between every projection view. What you really want is something like


AngularIncrement=180/size(I,2);
 IR=iradon(I,AngularIncrement);

"Matt " <xys@whatever.com> wrote in message <hdp3s4$og4$1@fred.mathworks.com>...
> "Alper Ozturk" <alperozturk83@yahoo.com> wrote in message <hdoks1$rbg$1@fred.mathworks.com>...
>
> > IR=iradon(I,360);
>
> Read the help doumentaiton on iradon again.
> The above is telling iradon() that there is a 360 degree angular increment between every projection view. What you really want is something like
>
>
> AngularIncrement=180/size(I,2);
> IR=iradon(I,AngularIncrement);

Oh great! Now I got it...
Thanks for the help...