thanks for uploading this. I am a biomedical engineering student and for one of the problems on our homework we have to draw a sinogram (by hand), but I'm trying to figure out how to do it in matlab first. It has been very hard to find good info online, seems like a niche topic.
I’m glad you find it helpful. If you check out the tomography playlist I give a pretty exhaustive discussion of the Radon transform into other lectures. That includes discussions on how to draw a sinogram.
If you start with the sinogram, you dont need to do the radon transformation in the first place. BUT what would you feed the iradon? It doesn’t work with a picture of the radon transform. Thanks in advance.
It might come down to the parameters. iradon makes a bunch of assumptions of where the center of the data is. And you have to be careful of the angles you feed it. iradon otherwise is just filtered back projection, which is pretty standard
@@JoelRosenfeld I‘ve seen your other Video (pseudoinverse and radoninverse), great by the way. Still got the same problem you start with a phanton, radon tranform it so you have a „radon matrix“ then you transform it back. But when I tried it with an image of a sinogram, I got an error that the sizes of the image matrix and of the radon matrix are not the same. Is there any methode to convert the image matrix to radon matrix?
@@spectra6995 could it be that your sinogram corresponds to fan beam geometry? This is for parallel beam, and matlab has a separate routine for fanbeam
thank you ; in back projection we calculate ,u in every position and we put the result in memory . the passage from (xy) to memory needs the transform radon. back projection and radon are linked together please another question and excuse me what does mean phantom .
Phantom is a common term for a dummy test function. Like a a function that is 1 inside of a circle and zero outside. The idea is that gives you a benchmark to see how your algorithms work. Often they are arranged in a particular way to mimic what you might see in a typical CT scanner.
TH-cam has a free music library that can get you started. For other music I reached out to the artist, such as Craig Hardgrove. And then there is a subscription service through Epidemic Sound that you can use for $15 a month.
The radon transform applied to a function of two variables is an integral along a line going from infinity to infinity. A line can be defined in terms of an angle and a starting position, which makes the radon transform a two variable function. The backprojection the average of the radon transform at every line going through a particular point. It can give you back a blurry version of the original function. The FILTERED backprojection gets you the original function back. Poke around my playlist on Tomography here. I have a full course explaining everything.
I used the same Matlab toolbox for my recent project. very simple and user friendly toolbox
It is a nice toolbox! I was a bit relieved when I realized I didn’t have to code my own Filtered Backprojection algorithm
please could you give me an idea about randon projection
what is the relation betwenn radon and back projection
what is sinogram
thank you
thanks for uploading this. I am a biomedical engineering student and for one of the problems on our homework we have to draw a sinogram (by hand), but I'm trying to figure out how to do it in matlab first. It has been very hard to find good info online, seems like a niche topic.
I’m glad you find it helpful. If you check out the tomography playlist I give a pretty exhaustive discussion of the Radon transform into other lectures. That includes discussions on how to draw a sinogram.
Hi,I want matlab code for phantom ,who makes the conversion voxel to stl ،can u help me please
If you start with the sinogram, you dont need to do the radon transformation in the first place. BUT what would you feed the iradon? It doesn’t work with a picture of the radon transform.
Thanks in advance.
It might come down to the parameters. iradon makes a bunch of assumptions of where the center of the data is. And you have to be careful of the angles you feed it. iradon otherwise is just filtered back projection, which is pretty standard
@@JoelRosenfeld
I‘ve seen your other Video (pseudoinverse and radoninverse), great by the way. Still got the same problem you start with a phanton, radon tranform it so you have a „radon matrix“ then you transform it back. But when I tried it with an image of a sinogram, I got an error that the sizes of the image matrix and of the radon matrix are not the same.
Is there any methode to convert the image matrix to radon matrix?
@@spectra6995 could it be that your sinogram corresponds to fan beam geometry? This is for parallel beam, and matlab has a separate routine for fanbeam
thank you ; in back projection we calculate ,u in every position and we put the result in memory .
the passage from (xy) to memory needs the transform radon.
back projection and radon are linked together
please another question and excuse me
what does mean phantom .
Phantom is a common term for a dummy test function. Like a a function that is 1 inside of a circle and zero outside. The idea is that gives you a benchmark to see how your algorithms work. Often they are arranged in a particular way to mimic what you might see in a typical CT scanner.
@@JoelRosenfeld thank you lot
please others question
sinogram result of all tetha ( from 1 to 179) the global matrix of mu attenuation coefficient for different angle..?
Have you watched the other videos? I lay out what this all means there.
How did you use music without having to deal with copyright stuffs?
TH-cam has a free music library that can get you started. For other music I reached out to the artist, such as Craig Hardgrove. And then there is a subscription service through Epidemic Sound that you can use for $15 a month.
please I can(t understund what is radon transform
what is backproject
what difference or relation
thank you
The radon transform applied to a function of two variables is an integral along a line going from infinity to infinity. A line can be defined in terms of an angle and a starting position, which makes the radon transform a two variable function.
The backprojection the average of the radon transform at every line going through a particular point. It can give you back a blurry version of the original function.
The FILTERED backprojection gets you the original function back.
Poke around my playlist on Tomography here. I have a full course explaining everything.
Plz tell me how can I build a sinogram??
,,,
Hello Rama! Check out my lecture on the Radon transform. Everything you need should be there.
@@JoelRosenfeld what is sinogram