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Problem statement

The ability to image sketches hidden by layers of paint is a valuable asset to art purchasers in their attempts toexhaustively examine the works they collect. Art conservators value a painting's underdrawings for two main reasons. The firstis that underdrawings can be exploited as an aid in determining whether the painting is an original or a forgery, by comparingthe style of the underdrawings to those of an artist's other works. The second is that comparisons between a painting and itsown underdrawing can give new insights into an artist's creative process for that work of art. Underdrawing images are bestrevealed by near infrared (NIR) cameras because all paint pigments, except black, are somewhat transparent in the 900 - 1700 nm range . However, current NIR cameras that are sensitive in this wavelength range are exorbitantlyexpensive, typically costing around $50,000 . This leaves the market of small art museums and individual artcollectors unaddressed. We intend to deliver an NIR camera that meets or exceeds key imaging system parameters in this market,such as spectral range, image resolution, capture time, and portability, while also reducing cost below the $5,000 level.


Before the 1960s, there was only one way to examine a painting's underdrawing: the layers of paint in front of the underdrawing had tobe removed, thereby destroying the painting in the process. This was unacceptable for multiple reasons. Since underdrawings are typicallyof less interest than the finished painting, removing the layers of paint on top is not justified. Also, many interesting results comefrom a detailed comparison between the original painting and its underdrawing. This comparison is difficult if the paint layers mustbe destroyed to access the underdrawing.

J. R. J. van Asperen de Boer was the first to image underdrawings using NIR reflectography in 1968 . Previous attempts had used an NIR camera to passively capture light inthat range. However, with passive capture it was difficult to see through pigments such as green, since most of the lightcollected was in the range of 750 - 900 nm, which is below the range where those colors are transparent. Boer solved thisproblem by capturing the reflected light from a tungsten lamp that produced radiation of wavelengths up to 2500 nm, giving amuch clearer image of the underdrawing. While Boer's design has been improved in numerous ways during the past four decades, itremains fundamental to most techniques for imaging underdrawings nondestructively.

and below are examples of comparisons between original paintings and their underdrawings ascaptured with a typical modern NIR camera. In , the underdrawing shows that the man in the top hat, the artist'saccountant, was initially looking towards the viewer, but later this changed so that he looked away, purportedly because ofdisagreements between the two men . In , a large arrow can be seen on the chest of a horse on the underdrawing of a painting by Laib. This arrow is absentfrom the overlaid painted image.

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Nir single pixel camera. OpenStax CNX. Apr 29, 2008 Download for free at http://cnx.org/content/col10525/1.1
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