Maurizio Seracini is a pioneer in the use of multispectral imaging and other diagnostic as well as analytical technologies as applied to works of art and structures, his remarks shed some light (both figuratively and literally) on this process.

This is sort of an unusual, a very unusual profession. But hopefully it will become very much more well known and popular as we move forward. We must try to remember that we also have not just virtual reality but we have a past that is very real and there is a lot that is still unknown and has never been seen which is worth pursuing and creating images of, we can say, the invisible or the unknown past. Specifically when this idea is applied using high tech solutions to our cultural heritage it might come out very interesting, not only ideas but results that will benefit all of us - and will link ourselves together because very often we tend to see the future without remembering that whatever we want to show, visual or non-visual - it's nevertheless very much tied to the past.

Our cultural heritage is more than just something that was done beautifully or that is part of our culture - it's something that we are the product of. And I think I want to show you some examples of how you can do that and this could be the leading edge for many other fields to come. For example, it could be in the industry, or it could be in the medical field just to mention a few.

So, I collect lost Leonardo images as habit, but we are now very much involved in searching for a lost mural by Leonardo da Vinci, called in the hall of the five hundred in the palatzo vecchio but I'd like to start with a piece of art that is a painting by Leonardo, called the adoration of the magi which is in the Uffizi, and I just want to give you an idea of what it means 'generating images' - generating the invisible but yet generating culture as well as objective knowledge.

Using science this time, not virtual reality, this is a sort of a challenge from the past for the future which I think can be inspiring to some of you. So let's take a work of art that everybody has seen, or we have read, or we can see duplications of images wherever in the world. Well there is still much that doesn't meet our eyes that is there to be known, that can be even more valuable then what we see with just our naked eyes.

But first let's see the approach. The methodological approach to study - in this case a masterpiece - but just leave it up to your imagination that this can be done practically for any other object, structure, I'll leave it up to you. So first of all just to pick it up from the medical field we just apply the same principle of comprehensive study which deals with analysis - which in this case is the art history research, and then the study of the anatomy and the pathology of, in our case, our illustrious patient using all sorts of different technologies starting with human diagnostic imaging followed by analytical diagnostics.

So, nothing new if you wish but let's try to use it on a different environment and see what can generate. We are so used to think of patients, real patients, but works of arts are also patients. They are older than us definitely, but their decay process is just equivalent as many of our pathologies and you'd be surprised how many of the technologies out there used in the medical field can be applied to our cultural heritage.

If we were to consider just multispectral diagnostic imaging, as its been applied entirely in the medical field or as, I think, integrated better as we have done it in the world of cultural heritage. You'd be surprised to find out that, using not only different technologies, but spread generating different images between 50 microns and 500 microns - how much we can discover there. If that were to be applied in the medical field today - it would not be possible, why? For one thing we have solved a very important problem of geometry. In other words, all of our findings, regardless of the technology we've been using - generates images that can be overlapped because regardless of the resolution they have at the end, because they have the same geometry. Which is not the case of the MRI, TAC, or any other visual diagnostic imaging technology in the medical field or any other fields for that matter.

So just imagine that all these different wavelengths, and several others that I'm not going to show you, that is visible in just a few microns. So that is medically what is the thickness of a painting layer, right? We're not talking about centimeters, we're not talking about meters, we're talking about microns. And look at just using different wavelengths, how much we can generate and in the process of going in depth in the work of art. We use different diagnostic imaging and we generate a sequence of many images never seen because they are the byproduct of the interaction of the fading in and out different images gathered with different technologies.

Well as I mention to you before the geometry - that's a key point, hardly to be underscored. We consider properly what is the geometry as the key element in providing the base to stitch, if you would, the depth - if you want to adapt, if you want to relate any image in any wavelengths that you capture into the same geometry. First of all we want to gather a very appropriate, precise, geometry in this case without the 3d modeling, structured light of a painting with the precision - and this was in 2003 with 250 microns, now we can go down to 25 microns precision. So we generate a 3d model and then all those images that you have seen, gathered with different technologies, were just plastered over.

So not only we have there a template to refer to, just try to imagine what could be done if these principles were applied for the human body. You could go from the skin to the skeletal system, in and out and check in the 3D model. Alright, let me show you just a little bit of some of the rendering that we get. Obviously it somewhat needs to be interpreted just as it's like for a radiologist, we need to be very much embedded in this field. These are some of the representations just of the back. You tend to see a painting and think to paint is a two dimensional work - it's not at all. It is a three dimensional work, the z-axis is a matter of microns, but that doesn't mean that it's not so important. The z-axis is what gives the texture which is especially important in a work of art, even down to the texture of the drawing.

This is discovering the new world that is there. It's discovering the genesis of the work of art because we can go from the very first moment of creativity of the artist as I'm going to show you, all the way up to the surface and backward - choosing the depth at which we want to understand and to visualize not only the genesis but also the decay processes. For example, where decay has occurred, and try to find a relationship between cause and effect. So just to give you an idea, a visual idea, of what I'm talking about, let's suppose we - this time I'll just pick one at random - have a wavelength let's say in the range of the infrared. In this case its up to 2.2 microns. So if we have a camera that operates up to that wavelength spectrum we can then become, thanks to the transparency of the pigments to that wavelength, we can capture what is under the surface and, in this example, it's a mosaic of 2400 IR reflectograms, which then later will be stitched to form something of what you will see.

So let's suppose we are standing in front of this painting and we think we know what we're looking at - we actually don't. As a matter of fact, we are just looking at 500 years of time passing with all the modifications that that has produced. Now in a way, without being offensive, but it is like seeing the virtual reality of a work of art without really seeing the true essence. There is a whole wealth of knowledge under that surface that needs to be retrieved because we can visualize it, and only when we have visualized it we can say we have a full understanding of the process used by the artist to create the masterpiece.

So let's have a view of the image on the left hand side and see how we can penetrate all through the thickness of the paint layer and see the drawing, I refer to the drawing that the artist sketched. Right on the ground, but we don't see it - BUT it is there. Don't you think its relevant to see the most important moment of creativity of the artist when he transferred the idea from his mind to the medium, to the, in this case, the ground layer of the battle/panel painting? You can see how beautiful portraits have been unveiled and yet they are there hidden for centuries. Now that is why I call, generating new knowledge, generating new culture from the past using high tech technologies, yet this not at all virtual reality. You're looking at the real thing.

So let's see another example. See the head on the horse just to give you an idea of how much we can really understand - very much more. So you see two heads, you see details, in other words you see the very first moment when the idea was transferred from the mind of Leonardo. And we are talking about one of the most important paintings, world known, just imagine if this wealth of knowledge, as in one painting so supposedly so well known - how much we can do more worldwide, in all different cultures. It's just the approach that needs to be revised to generate the true knowledge, or I should say objective knowledge talking about it from a scientific point of view.

Another detail that was never seen before, just on the upper right part of the painting - just another detail, its just a part of the, as I said, just a part of the richness of discoveries in just one painting alone. Now we're talking about our own culture. We are generating images - they are there, but they've never been seen before. Well what that brings, lets try to adapt to full to put exploitation of this idea.

How about a clinical chart of a work of art? In this case a virtual container, where we feed in all that we have learned, all the new generation of knowledge that we have provided thanks to this totally different approach of understanding. Or we have tried to exploit the true knowledge of a work of art - but it could be of any object. So a clinical chart as the first step to do also monitoring of the same work of art later on. Once you have established what is the pathology, all the pathologies, where are they located, why? Which means that you're able to do preventive conservation, which is a concept that is still not quite accepted or quite defused in the medical field. Or at least in medical terms, it surely is not as much as it could.

So by the way, I'm coming from the biomedical field and I'm a biomedical engineer, many, many, too many years ago. A clinical chart of a work of art is not that different from a real clinical chart for a patient, as I mentioned to you, you have anemisis (phado, meno) and then you get all the different layout, and finally you have the true diagnosis - so you'll know what to do with it. You know how to cure it. What kind of a restoration - we have this process initiated at the San Diego Museum of Art and already we have covered three works of art and hopefully we intend to show a new methodology also to other museums.

Let's take another example, this time let's go from microns to meters - let's see if that is feasible as well. So let's take the search for the lost Leonardo mural "in the hall of the five hundred in the pallazo vecchio". Hopefully all you will have the chance to go in the hall of the five hundred, since its in one of the most important buildings in Florence. Well Leonardo did paint a masterpiece between 1505 and the beginning of 1506 and it was depicting a major victory of the Florentine army, fought in 1440. This is the problem, it's very simple to define - very difficult as a test: Given the hall of the five hundred, how do you go about looking for a lost mural by Leonardo without touching anything? And knowing that this lost mural is behind one of those walls, and not just behind some paint - no - its behind another wall that's between two walls. As a result of a long, pretty long study, but I'm just trying to summarize.

First, again as we've done with structured light - this time laser scan. This is a study that started believe it or not, way back in '75, and was picked up again in 2000. So we got a first draft of the many additions to the hall of the five hundred from both sides and also underneath and all this was done with a precision of one centimeter in 2000 - but now we can go down to one millimeter. So again the principle of the geometry first, get it to the mathematical model. But then how do you explore, again a structure, in this case centimeters or meters thick, without touching anything? Yet we want to be generating knowledge that is there, which an integral part of the understanding of the overall structure since it was created and all the modifications that happened to it since.

So this time we used another technology that was known all the way back to the Vietnam war but we just used it for another purpose. So see this example. Let's suppose you have a facade. That's what you see with your naked eye. It's actually using your eyes, but there is another reality which is there, which we can see just not using our proper eye view, if you wish. So lets go under that last layer and what you see is the layout, the original layout of all these different windows being filled in about a century and a half before the actual state. So again, you are seeing objective knowledge, objective subject, objective results. There is nothing here that we are creating that is not there.

But its very important to understand the true essence of the object we are studying. So what about if we want to go farther inside the thickness of the walls, we want to understand beyond that plaster beyond the wall that Vasari the Medici Architect set up in 1568, from '63 up to '72 when he was ordered to remodel the hall of the hundred? So we use this time, radar - different frequency, different way to apply it then the radar we use to visualize the air, airplanes and traffic control. So, for a moment let's suppose we want to go through that front layer, that front wall, we want to see what could be underneath. So first we have completed this mosaic of over 1600 thermal images and you can see that you can spot every single stone and brick and that gives you an idea of all the changes. Obviously you need a background in the history of architecture and the history of materials, and the techniques of the construction of monumental buildings in order to understand what you're looking at.

Well then we are going through, going over, moving forward inside that first double wall structure and we wanted to find out if there was a gap, an air gap, behind the air wall, behind the brick wall. Why? because Vasari did save other masterpieces just by placing a brick wall and leaving an area, so maybe this was the case. So we scanned the entire hall of the five hundred searching for an area and we managed to find, on the right panel of the east wall, indeed a very strong signal, generating at an interface at the very end of the brick wall and this is the collection, it's this radar sequence of the three panels radar displayed which were taken after a direct time delay in order to collect the signals right after the end of the brickwall which is underneath the Vasari's mural. And as a matter of fact, we managed to prove that there is indeed, in this area, an air gap.

And this is where the strong signal was generated right after the thickness of the brick wall. But if we would like to see it in some reconstruction, you will see that after the brick wall, which is the base for the mural there is an air gap and the radar image shows indeed a very strong signal associated with the gap. And we could go in that area recording, now we are generating 3D images of, rather than just radar maps. So that we will be able very shortly to be able to go from the surface of an object all the way inside generating this visual understanding of the inner structure. So this is more or less what we have learned so far putting together these different technologies so that with Vasari's mural on the brick wall and placing over an air gap and that's where, this is where the recollection of the, how the so-called Salagrande was at the time that Leonardo started to paint.

So we have not taken guesses, we have searched for objective images, real images in order to reconstruct the past. And obviously this is a virtual reconstruction and everything that you see but the benches, the wood benches, those come from reading original documents are indeed related to real data that we have gathered.

So what is in front of us, where are we headed following in this path, this new approach to reality? For example, we are starting now x-ray based scattering and reference imaging, nuclear techniques such as neutron activation analysis, prompt gamma neutron activation analysis, and neutron activation spectroscopy. Those are all new technologies that we are going to apply in order to go father in, in very thick structures made of any materials whatsoever.

All this begs the necessity to create a new field and create a new breed of scientist and we call it cultural heritage engineer but if you want its an engineer that using all the different fields of engineering sciences, its able to study the invisible creating new objective knowledge of objects around us. So it doesn't want to sound contradictory to what all of you are familiar with - talking about virtual reality or future. This indeed is the future, but is generating more knowledge of our past which will allow us to understand, not only technology of the future, but also how these technologies should be used.