What is tomography?

[@lukeconnell215]

Wow, one of the most informative videos I've ever seen on the topic! I love this video

[@Samuntiedekanava]

Thank you so much!!

[@danlior8682]

I'll just repeat the popular sentiment. This video is an incredibly clear, and even entertaining, description of the most fundamental reconstruction algorithm. Thank you for creating and posting it Samun. I would love to see further videos on the same topic.

[@Samuntiedekanava]

Thank you so much! For further videos coming there soon, and all in English, check out my new Inverse Problems Channel.

[@rommelreal9114]

I've been studying inverse problems and tomography in a while, and by far this is the video that explains the subject best! Wish I watched this earlier!

[@Samuntiedekanava]

I am happy to hear that! Check out my other tomography videos at www.youtube.com/@professor_sam

[@alvinb.kimbowa1239]

This video is unbeliveably clear, concise, practical, and very easy to understand. It's mind blowing that I have understood computed tomography in less than 20 minutes. I've been trying to understand it for over two weeks. Thanks Samun for this amazing video.

[@Samuntiedekanava]

I’m so glad to hear that! 😄 You might want to check out my newest videos on this topic on my new channel www.youtube.com/@professor_sam

[@SurajGupta]

Simple and fantastic way to explain the concept. Very very interesting.

[@Samuntiedekanava]

Glad you liked it! 😃

[@Samuntiedekanava]

Check out my other channel www.youtube.com/@professor_sam as well!

[@hongyuli5490]

OMG. This instructor is Amazing!

[@Samuntiedekanava]

Thank you! May I also recommend my follow-up video Introduction to Sparse Tomography

[@dongliu2650]

Ihan hyva. Excellent introduction and nice scenarios. kiitos Samu.

[@Samuntiedekanava]

Dong, thank you so much! 😃👍🏻

[@haythamali6906]

Thank you for this wonderful and simple explanation. I hope to see more lectures to you in the future face to face or in this channel. I was lucky to have met you and listened to your presenation in Japan. I hope we will meet again.

[@Samuntiedekanava]

I am glad to hear that you liked it! I’m looking forward to seeing you the next time. Meanwhile, check out my new channel “Professor Sam”. I have more lecture videos in English coming up soon.

[@agargamer6759]

Thank you for this illuminating explanation! Some beautiful technology and mathematics underlying what is now a routine hospital scan

[@Samuntiedekanava]

I'm glad you liked it! CT is indeed a wonder combining mathematics, physics, medicine and engineering.

[@koushikpaul5908]

This is one of the best explanations I have ever experienced! Thank you so much for this wonderful video!

[@Samuntiedekanava]

Well, you’re welcome! I am very glad you found my video informative. It is the result of many, many talks and presentations through which the material took form.

[@AnweshaKhasnobish]

Thank you for this most simplistic yet insightful explanation of the topic

[@Samuntiedekanava]

My pleasure! I’m so glad you liked it !

[@lauri2253]

Aivan huikea video, kiitos!

[@Samuntiedekanava]

Lauri22, hauska kuulla!

[@vinitpandya02]

Excellent explanation! I couldn't get a better non-mathematical explanation from a mathematician! 😄

[@Samuntiedekanava]

Thanks! I’m glad you like it! 👍🏻

[@yelyzavetapulnova4305]

Amazing and comprehensive explanation ! Thanks a lot 🙏🏻

[@Samuntiedekanava]

Thank you! I am so happy to hear that you liked the video! 😀

[@dHewlett]

This is fantastic! Sharing it with my Tech Bandit kids this week! Thank you so much... funny, smart and informative!

[@Samuntiedekanava]

dHewlett, thank you so much! I am so glad to hear you like the video. I did have a few test runs before the material found its final form... 😃

[@Samuntiedekanava]

dHewlett, next in the series are coming up videos on sparse-angle tomography, limited-angle tomography and time-dependent imaging. That takes us to current science.

[@Samuntiedekanava]

Here is a sequel: kzbin.info/www/bejne/mJzJfXx_hducjpY

[@moienr4104]

I am learning about Satellite Radar Tomography, and still, your video cleared a lot of things up! Thank you!

[@Samuntiedekanava]

I am so happy to hear that! You might also enjoy my other channel's tomography courses: Tomo 100: kzbin.info/aero/PLQpXdScJ5T8VNlc8QQCQpY5FoIJQKaOhY Tomo 200: kzbin.info/aero/PLQpXdScJ5T8XclTPW8WvyZVlP7PCem_mw

[@toomuch_thyme]

I love this, I started for knowledge, and finished for the entertainment!

[@Samuntiedekanava]

Excellent! I am so glad to hear that! 😃

[@anitha998]

You Sir are amazing! Loved how well you've explained this rather difficult concept!

[@Samuntiedekanava]

Thanks, Anitha! It developed through dozens of lectures, conference talks and school visits. Step by step I added animations, explanations, and of course, jokes. 😃

[@Fdan36]

@@Samuntiedekanava thank you Sir. Your explanation of the development of the development of the video is as enlightening as the video itself.

[@FirstnameLastname-fd9cp]

Excellent video. This was quite infomrative and has provided me with a good starting point to learn about this subject. Thank you for this.

[@Samuntiedekanava]

I am so happy to hear that! 😃

[@Samuntiedekanava]

Please check out my new channel “Professor Sam “. I am building there a comprehensive video series on this topic. So far there are two: Tomography 101 and 102, and soon will be more

[@FirstnameLastname-fd9cp]

@@Samuntiedekanava brilliant, I'll be sure to check out this channel.

[@harshalshirodkar8399]

Nothing can be more clearer than this ❤

[@Samuntiedekanava]

Check out Tomo 100 kzbin.info/aero/PLQpXdScJ5T8VNlc8QQCQpY5FoIJQKaOhY

[@harshalshirodkar8399]

Sir, I have already gone through your tomorrow 100 playlist ❤❤

[@TomajJavidtash]

Great video and intuitive explanation. Thank you!

[@Samuntiedekanava]

Thank you! You might also like my new channel: kzbin.info/aero/PLQpXdScJ5T8VNlc8QQCQpY5FoIJQKaOhY

[@laurensullyx]

Great video! Best ive seen on the topic, feel like I actually understand now

[@Samuntiedekanava]

Great to hear! I did dozens of test runs with this material, so it did evolve step by step into more understandable form. I am so glad you like it.

[@jorgeluisochoa2704]

Superb way of explaining. Congrats! I really learned something amazing today?

[@Samuntiedekanava]

Thank you! I am so happy to hear that. This video is a result of dozens of talks and lectures, gradually improving the way to explain. There is a sequel (kzbin.info/www/bejne/mJzJfXx_hducjpY), and more on the way.

[@shrabanmonir]

Very nice video. Helped me a lot to understand the topic. Thank you.

[@Samuntiedekanava]

I am happy to hear that! 😃👍🏻

[@paoloose]

I really loved this, such a wonderful explanation

[@Samuntiedekanava]

Thanks, Paolo! Please check out my new English channel for more: www.youtube.com/@professor_sam

[@Anilkumar-zz6lo]

Wow superb explanation sir. Loved tour style and the content.

[@Samuntiedekanava]

Thanks, Anil! Much appreciated.

[@lwendt1]

This is GREAT! I'll check out more videos!

[@Samuntiedekanava]

Thank you so much! 😃

[@mdmubaraq]

Thanks for explaining complicated subject in a simple way

[@Samuntiedekanava]

You’re welcome! I am very glad to hear that you liked the video. I believe that even complicated math can be explained in an understandable way.

[@Samuntiedekanava]

Mohamed, you might like this one as well: kzbin.info/www/bejne/gJCvl2h7ed6SjcU

[@dianac4480]

Great explanation! thank you!!!

[@Samuntiedekanava]

Thanks! I am glad you like it!

[@tamerdawud6930]

Nice and easy explanation, Thanks!

[@Samuntiedekanava]

I’m glad to hear that you liked it! 😃👍🏻

[@tedwang2996]

very clear Pronunciation，and idea ez to get, love it!

[@Samuntiedekanava]

Thanks, Ted! I’m glad you like it! 😃

[@julioreyram]

Hahahaha so much fun while learning amazing stuff, what a lovely guy!!

[@Samuntiedekanava]

Thank you! I’m glad you liked it! 👍🏻

[@xiaogecheng3335]

Interesting explanation, love it ! 👍🏻👍🏻👍🏻

[@Samuntiedekanava]

Thanks! 😃

[@VarunJS45]

You are a very good teacher. Love from India 🙏

[@Samuntiedekanava]

Thank you so much! 😃

[@deudaux]

Thank you, this is great!

[@Samuntiedekanava]

Nice to hear! Check out my new channel www.youtube.com/@professor_sam There will be a full course about the same stuff but going eventually deeper

[@AbhishekPandey-qj7nk]

you are a lifesaver Professor

[@Samuntiedekanava]

Thank you so much! 😊

[@TSSomensi]

Outstanding content!

[@Samuntiedekanava]

Thank you! 😊

[@ErichAmMeer]

INCREDIBLE VIDEO!!!!!!!

[@Samuntiedekanava]

Thank you so much! ☺️

[@JollyJackfruit]

Excellent video 👏👏👏

[@Samuntiedekanava]

Thank you! 😃

[@abhishekjadhav5957]

Wow.. Logarithm is useful... Amazing..

[@Samuntiedekanava]

Yes, logarithms are useful! Another application of logarithm is radiocarbon dating of ancient objects.

[@ahmedshaheen9759]

Wow!! Thanks a lot. I am seismologist. We send sound waves into the ground and measure the response. Quite an analogous field. Thanks a lot. It helps to understand a lot of papers in the field. Is it possible to make videos for tests similar to those in this video but with the Math behind ? Thanks again

[@Samuntiedekanava]

You can find the math in my lecture videos, for example in this playlist: kzbin.info/aero/PL5Ai_qOtp0HSVe3V8fmxDZvwHyDeTv79o

[@rakshitp9124]

This is so good. Thank you so much :)

[@Samuntiedekanava]

Thank you! I am so glad to hear that you like it! 😃

[@vegetablebake]

Very helpful, thanks.

[@Samuntiedekanava]

Thank you so much!!

[@matan9064]

Great video, Thank you (and I like the unicorn!)

[@Samuntiedekanava]

Thanks! Science communication needs more unicorns 🦄

[@sridharvinod8667]

great explanation. thank you.

[@Samuntiedekanava]

Thank you so much! I am so happy to hear that you liked the video.

[@Mark-te8ky]

cool video! 😊

[@Samuntiedekanava]

Thanks!!

[@spider853]

Thanks for such a wonderful video! I was wondering wouldn't the edge filter in the 2 disc scene result in 2 hollow circles?

[@Samuntiedekanava]

The photo example is indeed a bit exaggerated, for clarity. For example, it involves taking the absolute value, which the FBP process does not use. But in FBP the filter just perfectly removes the blur. If you apply it another time, though, you would indeed see two hollow circles!

[@sharonshajan6995]

thankyou. this is very good quality content..

[@Samuntiedekanava]

I am so glad you like it! It is developed as a result of dozens of seminar talks, conference presentations and school visits.

[@yelectric1893]

Beautiful

[@Samuntiedekanava]

Thank you!! :-)

[@rohandeshmukh1815]

Great video thanks! But why are your other videos in other language (probably finnish)

[@Samuntiedekanava]

There is so little science stuff available in KZbin in Finnish! I am trying to offer Finnish kids starting points to math and science. However, most videos have English subtitles. And: check out Inverse Problems Channel, for example this video: kzbin.info/www/bejne/gJCvl2h7ed6SjcU

[@ranitroy7994]

Thank You so much for this beautiful explanation. I have a question about the filter that you are using in the Fourier Space. With the increase in the amplitude in the Fourier space there should be an increase in the Noise. Is that an issue faced with the current system?

[@Samuntiedekanava]

Indeed it is an issue. In practical FBP algorithms there is a variety of high-frequency cutoff or suppression filters. For example, instead of indefinitely increasing the frequency response linearly, it may become constant outside a disc. In this presentation I chose to talk about the ideal mathematical situation only, for brevity.

[@ranitroy7994]

@@Samuntiedekanava Thank You so much for the explanation.

[@tongzhou4997]

hello kitty is definitely a highlight

[@Samuntiedekanava]

I think so, too!

[@Anilkumar-zz6lo]

Sir please make some video on FFT and Image processing techniques.

[@Samuntiedekanava]

I will! Right now I only have this, and unfortunately in Finnish. kzbin.info/www/bejne/pJzGk35um6eMask

[@frodobaggins3974]

Back projection... It amazes me that this method is still widely used. We now have many better algorithms, and contemporary computers have the power to handle them. SIRT would be one example, but there are others.

[@Samuntiedekanava]

However, iterative algorithms such as ART, SIRT and variational regularization, do make use of the transpose of the measurement matrix. And that is actually (unfiltered) backprojection. So it does stay relevant! 😃

[@emmah3514]

May I reuse 5:28 to 5:38 to illustrate how reconstruction works in my school presentation? I'll be sure to give you credit!

[@Samuntiedekanava]

Sure, please go ahead! That’s why I made the video: for spreading information. 😃👍🏻

[@emmah3514]

@@Samuntiedekanava thank you so much :D

[@ilpokantonen6129]

Entä jos kappaleet eivät ole staattisia? Luulen, että liikkuvia kappaleitakin voidaan kuvata tomografialla. Liikkeitä voi olla kahdenlaisia: paikka liikkuu tai muoto liikkuu. What if the object isn't static? I think that moving objects can also be imaged by tomography. There are two types of movements: the place moves or the shape moves.

[@Samuntiedekanava]

Erinomainen kysymys. Tämä on yksi tutkimusaiheistani parhaillaan. Liikkuvan kohteen kuvaaminen onnistuu kohtuullisen hyvin esimerkiksi videon käsittelyyn kehitetyn optisen virtauksen avulla. Täytyypä tehdä oma videonsa siitä!

[@HeikkiMakes]

Olipas mielenkiintoinen ja ihan sattumaa että tässä lounaalla tämän katsoin. Meille on töihin ehkä tulossa joku 3D röntgen skannausvärkki jos saadaan hankerahoitus kasaan. Sillä pääsisi ilmeisesti nanotarkkuuteen ja kappaleet olis jotain nyrkin kokoisia. Yritysten rahaa puuttuu...

[@Samuntiedekanava]

Heikki Makes, kuulostaapa mielenkiintoiselta! Juväskylän yliopistossa muistan myös nähneeni nanotomografialaitteen noin kymmenen vuotta sitten. Kehitystä on varmasti tapahtunut laitepuolellakin!

[@HeikkiMakes]

@@Samuntiedekanava Luulisi ainakin hintojen tulleen alaspäin. Tämä laite, jos hanke toteutuu, tulee Mikkeliin Xamkille (Kaakkois-Suomen ammattikorkeakoulu).

[@Samuntiedekanava]

@@HeikkiMakes, aivan loistavaa.

[@jaswanthbeere3836]

amazing

[@Samuntiedekanava]

Thanks 😊

[@SundryTalesOfConstance79WESTY]

Nooice! 😎 STOC

[@Samuntiedekanava]

Thank you!!

[@jegadeesangovindarajan972]

nice work easy to understand ..... can we do the same animation in python

[@Samuntiedekanava]

Yes, definitely. You just need an implementation of the Radon transform. And a lot of coding.

[@sepidehmajd593]

The last moment is creepy, but the rest informative

[@Samuntiedekanava]

Thank you! 😃👍🏻👍🏻👍🏻

[@sepidehmajd593]

@@Samuntiedekanava I am going to do my master thesis in hydraulic tomography and it contains invers modeling, I saw one of your videos about inverse problems and that was wonderful, I appreciate it

[@AkhilVennam]

Sir, you made yourself these animations ? With those graphs ?

[@Samuntiedekanava]

I did the animations myself using MATLAB software. If you are interested I am happy to share them.

[@AkhilVennam]

@@Samuntiedekanava yes sir. I like them. Happy to have them. Really cool. My mail : [e-mail] Or else, share the link here sir.

[@FabledRanoo]

please i need books and sources about tomography ( not computed tomography ) but tomograph overall

[@Samuntiedekanava]

Check out Mueller&Siltanen: Linear and nonlinear inverse problems with practical applications (SIAM 2012)

[@FabledRanoo]

@@Samuntiedekanava thank you so much

[@desueilhalder1854]

Was studying synchrotron, looked for tomography, watched edward elric's father teaching about it :O

[@Samuntiedekanava]

Please check out my courses here: kzbin.info/aero/PLQpXdScJ5T8VNlc8QQCQpY5FoIJQKaOhY&si=RLYGGCfOVea8EUY3

[@Samuntiedekanava]

And here for iterative reconstruction: kzbin.info/aero/PLQpXdScJ5T8XclTPW8WvyZVlP7PCem_mw&si=7bGCyP8gOOBqpWN1

[@shannondoyle5143]

it's batman :D hahaha this is great, enjoyed the tests

[@Samuntiedekanava]

Great! I’m glad to hear that! 😃👍🏻

[@홓홓-m6x]

This is Great!!!ㄷㄷ OMG...ㅠㅠ

[@Samuntiedekanava]

Thank you so much! 😃

[@BlinkFU]

I dont know what i am doing here. I was searching for tomato and cheese pizza 😒. Well meh! I dont mind. Lets see what this guy talking about.

[@Samuntiedekanava]

Aaaaand I am talking about tomography! 😃

[@BlinkFU]

@@Samuntiedekanava ha ha ha 😂🤣thanks to you i've learnt something new. ✌💓

[@Samuntiedekanava]

Excellent! That is the goal of my video, after all. 😃

[@mohammedrayeesuddin6551]

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