So I promised that I would tell you in advance if we do a refresher course, but today we

do a refresher course and I didn't tell you in advance.

So if you attended Diagnostic Medical Image Processing you already know what we're going

to talk about today.

So if you get bored, feel free to leave.

This is more or less fundamental knowledge, but maybe it doesn't hurt to rethink about

it, but if you already know what homogeneous coordinates are and you are well equipped,

so then you will pretty much hear the same story as in the winter term.

Nonetheless, there is at least something new.

So I told you that there will be this excursion on May 18th and these are the details that

I promised.

So departure will be on May 18th and we will have to leave at 6.30 because the workshop

starts at 9 a.m. in Munich and we have to travel there by bus.

So we already registered a bus and so we will depart here at the computer science tower,

so at the building over there, at 6.30 already in the morning.

So it will be pretty early, but nonetheless we have already 18 people registered for the

trip and there's only 50 places.

So if you want to register, the bus ride will be free, I will bring breakfast hopefully

and you can register by sending an email to swengrünke at FAUDE.

He is assembling a list and if the places are full, he will tell you that there are

no more spaces.

But this is really a very nice workshop, so we have people from all over the world traveling

to Munich and they are actually deciding the final decisions on conference contributions.

But they will also give this workshop and you will be able to listen to several experts

and we will also put up the link to the website, but the website is not yet public.

So there you can see what speakers are coming to this workshop.

So this is medical image computing and computer assisted intervention and this is very closely

to related to the topics that we are referring here in the lecture and this is really a great

chance to get to know really well known people in the field and I highly recommend taking

part here.

So only 50 places, so please register as soon as possible if you want to make sure that

you get a slot.

Okay good, so much about the commercial.

Then we will start with the actual lecture and today we will do a refresher course.

So we will talk about projection models.

So projection models and homogeneous coordinates.

So I'm sorry I said that I would already tell you in advance when we do a refresher course,

but due to the, that we missed the Tuesday lecture in this week I didn't announce it.

I'm very sorry about that.

So who knows about projection models and homogeneous coordinates?

Okay so that's less than half.

There's still some people here to who this will be new.

So this is a really, really nice thing and it's very relevant because we'll be dealing

with projection geometries all the time.

And just one motivation, so commonly when you talk about projection models this is often

related to computer vision and there the cameras are really the devices that obey the projection

models.

And in fact we have that also in the medical imaging devices and in particular in x-ray

projection images.

So they also are formed by a projective transform and if we want to process x-ray images it