atsi bari, 5 september 2014 - enea · atsi bari, 5 september 2014 shroudshroud--like coloration,...

ATSI Bari, 5 September 2014

ShroudShroud--like coloration, conservation like coloration, conservation measures and image processingmeasures and image processing

A survey of experiments at ENEA FrascatiA survey of experiments at ENEA Frascati

Paolo Di Lazzaro Daniele Murra

A survey of experiments at ENEA FrascatiA survey of experiments at ENEA Frascati

Paolo Di Lazzaro, Daniele MurraENEA Center of Frascati

paolo dilazzaro@enea [email protected]

Outline

Th i th Sh d ST RPThe images on the Shroud, STuRP

Photochemistry-based linen coloration

Conservation measures

Misleading image processing

Conclusion

Paolo Di Lazzaro, ATSI 2014 Bari

The images on the Shroud

Recent Photo of the Turin Shroud (Courtesy David Rolfe)The two faint body images have a lower contrast and are lessy g

visible than all the stains thereabouts: blood, water, burns.


The STuRP Project

Torino, 8‐14 October, 1978.

32 scientists and technicians,

2.5 million $ equipment,

120 hours no‐stop analyses,

2 years for data elaboration


Main findings of STuRP The Shroud is not a painting, no pigment, any directionality, not a scorch.The image encodes cloth to body distance, and it is present in both contactg y , p

and non contact areas.The image is superficial, no more than 0.6 microns thick (work by others

has shown 0.2 microns).)Invisible halos surround blood.

Blood went on beforeimage (no imagebeneath blood).

The blood stains containhemoglobin and serumalbumin.

Calcium and strontiumand iron are uniformlypresent on the Shroudpin small quantities.


STuRP conclusion

“We can conclude for now that theWe can conclude for now that theShroud image is that of a realhuman form of a scourged,crucified mancrucified man.It is not the product of an artist.The blood stains are composed ofhemoglobin and also give a positivetest for serum albumin.The image is an ongoing mysteryThe image is an ongoing mysteryand until further chemical studiesare made, perhaps by this group ofscientists or perhaps by somescientists, or perhaps by somescientists in the future, theproblem remains unsolved.”


Outline





Conclusion


Why photochemistry? Why UV?

E i d b h l h di i b k h i lEnergy carried by short-wavelength radiation breaks chemicalbonds of the irradiated material without inducing a significantheating (photochemical reaction)heating (photochemical reaction).Moreover, linen has a molar absorptivity which increases whendecreasing the radiation wavelength: the smaller the wavelength,the thinner the material necessary to absorb all the radiation.

Th h h th lt i l t di ti “ ti tThen, we have chosen the ultraviolet radiation as an “acting atdistance” mechanism to obtain at least two of the maincharacteristics of the Shroud image: a thin coloration depthcharacteristics of the Shroud image: a thin coloration depthand a low-temperature image-formation.


How much different is our linen from the Shroud?

The solid lines show the absolute reflectance of the linen of the Shroud in areas ofno-image as a function of the wavelength (Gilbert, Appl. Opt. 1980).

Th d h d li h h b l fl f h li d i iThe dashed line shows the absolute reflectance of the linen used in our experiments.From J. Imag. Sci. Techn. 54, 4302 (2010)


Set-up at ENEA Frascati

Hercules ENEA PBUR

6 J, 120 ns, 5 Hz

308 nm308 nm

LPX 305 PBURLPX-305, PBUR

0.5 J, 30 ns, 50 Hz. 308 nm o 193 nm


Ultrashort UV pulses irradiate linens


Short movie

Excimer laser irradiation of linenExcimer laser irradiation of linen


Linen thread after 10ns, λ = 193nm irradiationirradiation

From J. Imag. Science Techn. 54, 040201(2010)Paolo Di Lazzaro, ATSI 2014 Bari

Depth of coloration: UV vs. VUV

λ = 193 nmCross section of irradiated linen

threads

λ = 308 nm

Di Lazzaro, Regina Apostolorum 9/4/14 Paolo Di Lazzaro, ATSI 2014 Bari

Sometimes VUV does not color the scwinside the fiber

N h ll ll i h i f b kNote the small yellowish pieces of broken pcwFrom Applied Optics 51, 8567 (2012)


Latent images generated by VUV

Paolo Di Lazzaro, ATSI 2014 BariUnpublished

Half-tone effect by VUV irradiation

Microscope view of linen threads after VUV laser irradiation. Single colored fibers are visible next to uncolored fibers like in the Shroudcolored fibers are visible next to uncolored fibers, like in the Shroud image (areal density coloration). From Applied Optics 51, 8567 (2012)


Cold or thermal coloration?

λ = 308 nmT = 21 °C - 34 °C

λ = 193 nmT = 22 °C - 25 °C


Short movie

Th i l t tl b hThe excimer laser as a contactless brush

LBS

ℓPD

EXCIMER LASER

OSOS


Shroud-like face using excimer laser as a brush

The face image produced by laser shots is very faint, invisible at sunlight. Only in shadow we can perceive a low-contrast yellowish faint image

Unpublished Paolo Di Lazzaro, ATSI 2014 Bari

Only in shadow we can perceive a low-contrast , yellowish faint image.

Shroud-like face using excimer laser as a brush

The negative of the previous photos shows a positive image. The negative allows to see the single laser shots producing the very faint image.

Si 2013

The negative allows to see the single laser shots producing the very faint image.

Since 2013it is exposed

i th Min the Museumof the Shroud

i T iin Turin

Unpublished

Di Lazzaro, Regina Apostolorum 9/4/14

Unpublished


Outline





Conclusion


From cellulose to cromophore(conjugated carbonyl groups)(conjugated carbonyl groups)

Alkene –C=C – and ketonic carbonyls – C=O absorb λ << 260 nm

aldehyde ‐CHO absorb λ < 320 nm (large bandwidth) absorb λ << 260 nmabsorb λ < 320 nm (large bandwidth)

Aldehyde absorbs both 193nm and 308nm to generate cromophores. But only 193nm isabsorbed by alkene and ketonic groups, thus delocalising groups and shifting absorption band to longer wavelengths in the blue-green spectral region This causes the yellow

J. Appl. Polymer Science 16, 2567-2576 (1972). Cellulose 1, 205-214 (1994)Paolo Di Lazzaro, ATSI 2014 Bari

band to longer wavelengths, in the blue-green spectral region. This causes the yellow coloration.

Ionizing radiation vs. Shroud conservation

Gas Radon is the most dangerous source of natural ionizing radiation, potentially affecting the long term conservation of the image contrast and visibility.

Gases and pressureRelative

humidity, temperature

Box material / thickness

Radon issuetemperature

Our 99.6% Ne or Ar,

0.4% O2, RH ≈ 40%Al or Al-based

alloy

Building materials and objects aroundsuggestions 9 mbar water vapor,

P = 1,05 barT = 20 °C

alloyt ≥ 5 mm

objects around must be Radon-

free

Present li

99.5% Ar,0.5% O2 RH = 50% Al alloy, Information not

reliquary P equalized to the atmospheric pressure

T = 19 °C t variable available


From EAI, special issue on Knowledge, Diagnostics and Preservation of Cultural Heritage, pp. 89-94 (2012).

Outline





Conclusion


A hidden face on the back of the Shroud?

J. Opt. A: Pure Appl. Opt. vol. 6 pp. 491-503 (2004)

i i f dDeep image processing of a screenedphotographic reproduction of the backsidetaken from a book. Image processing toolsi l d d l ti ith G i filtincluded convolution with Gaussian filters,summation of images, gamma correction andfiltering in spatial frequency by direct andinverse 2D Fourier transformsinverse 2D Fourier transforms.

Sindon vol. 19 pp. 57-69 (2003)Direct and inverse Fourier transform of a high-resolution image directly obtained by in-depthresolution image directly obtained by in depthscanning of the backside of the Shroud, did not showany face or any other image.



A direct, in‐depth analysis on the Shroud shows there is no hidden face or any other imageon the backside of the Shroud. How can we crosscheck this result?

We checked both images on the left have the samehistogram of “number of pixels” vs. “gray levels”. Then,after the optimum spatial overlap of the two imagesafter the optimum spatial overlap of the two images(using bloodstains as a reference), the absolute value ofthe difference of gray levels between images should givea black figure when the two images are perfectlya black figure when the two images are perfectlycorrelated, or a noisy figure when they have a partialdegree of correlation, or a recognizable face whentheir correlation is poor.1.2 ‐ their correlation is poor.

1.0 ‐

ERCE

NTA

GE

BACK SIDE

0.8 ‐PIXE

L P

FRONT SIDE


0 50 100 150 200 250

GREY LEVEL

0.6 ‐

0.4 ‐

| | | | | |


A direct, in‐depth analysis on the Shroud shows there is no hidden face or any other imageon the backside of the Shroud. How can we crosscheck this result?

We checked both images on the left have the samehistogram of “number of pixels” vs. “gray levels”. Then,after the optimum spatial overlap of the two imagesafter the optimum spatial overlap of the two images(using bloodstains as a reference), the absolute value ofthe difference of gray levels between images should givea black figure when the two images are perfectlya black figure when the two images are perfectlycorrelated, or a noisy figure when they have a partialdegree of correlation, or a recognizable face whentheir correlation is poor.

their correlation is poor.

The result of this pixel-by-pixel calculation isshown on the left where a Shroud-like face can beshown on the left, where a Shroud-like face can bestill recognized, thus revealing the lack of spatialcorrelation of the images above, as a whole.


From Pattern Recognition 46, 1964 (2013)

No hidden face on the back of the Shroud

The lack of spatial correlation between the “hidden” face backside and the face on theShroud is further confirmed by a template matching based on a cross-correlation algorithmy p g gthat calculates the Pearson product-moment correlation coefficient S according to thefollowing equation:

0 4

where Aij (Bij) is the gray level of the single pixel (i j) of the image A (B) and <A> (<B>) is

= 0.4

where Aij (Bij) is the gray level of the single pixel (i,j) of the image A (B), and <A> (<B>) is the mean value of the gray level of the image A (B).When applying this equation to the front and “hidden” face on the back we obtain S = 0.4S = 0.4 is a very poor spatial correlation value, typical of completely different images.S 0.4 is a very poor spatial correlation value, typical of completely different images.

As an example, Figures on the left have thep , gsame correlation coefficient S = 0.4 of thefront and presumed back faces on theShroud


Why we perceive a face on the back of the Shroud?

In summary, both a direct, in-depth analysis on the Shroud and two different methods ofspatial correlation show there is no hidden face on the backside of the Shroud. It remains theproblem to understand why most of us can perceive a Shroud like face on the back if itproblem to understand why most of us can perceive a Shroud-like face on the back, if itdoes not exist.

The presumed face on the back actually contains 3 ‘faces’ at least…p yThe face-like patterns we perceive is possibly due to a combined effect of the brain’s abilityto supply the missing contours in order to make sense out of any pattern we can see and ofour innate propensity to interpret stimuli as faces based on minimal cues. As a matter ofp p y p f ffact, we are hard-wired to perceive faces from several random patterns!


Our psychophysiology mechanism ‘sees’ faces everywherey


How it works? Retrieving capability of our brain

Can you read me?Can you read me?

Can you read me?

When a phrase is in a context, our brain is able to retrieve its meaning even whenit i h lf ll d (G t lt ti i t i l dditi f th l t

y

it is half cancelled (Gestalt: perception is not a simple addition of the elements we see, but it is the result of the relations among the observed objects).A single letter, when half cancelled, cannot be retrieved (detail vs. context).

C4N Y0U R34D M3?C4N Y0U R34D M3?

The same ability of retrieving incomplete information holds for “looking like”


patterns (numbers instead of letters).

Outline





Conclusion


Conclusion• We have presented the first comprehensive survey of the

overall research work on Shroud-related issues done in thelast 8 years in the ENEA Research Center of Frascati.

• Our irradiations of linen fabrics show the ability of ultra-short,high intensity UV and VUV radiation to reproduce manyhigh intensity UV and VUV radiation to reproduce manypeculiar aspects of the microscopic complexity of the TurinShroud images.

• The different coloration results obtained in different irradiationconditions allow to recognize photochemical reactions involvedin our Shroud-like coloration, thus offering hints to plan thein our Shroud like coloration, thus offering hints to plan thelong-term conservation of both cloth and image of the TS.

• Our study of the misleading effects of digital image processingf l t t i fi th t th iof low-contrast images confirms that there is a narrow

boundary between image enhancement and manipulation. Ourresults corroborates previous works showing the absence ofany face on the backside of the Shroud.


Contributions from

Giuseppe Baldacchini ENEA FrascatippPaolo Di Lazzaro ENEA Frascati

Giulio Fanti P d U i itGiulio Fanti Padua University

Daniele Murra ENEA Frascati

Enrico Nichelatti ENEA Casaccia

Antonino Santoni ENEA FrascatiAntonino Santoni ENEA Frascati

Barrie Schwortz STERA Inc.

who gave a contribution to different phases of this long-term work and coauthored papers published in peer reviewed journals


Deeper insights may be found in

• G. Baldacchini, P. Di Lazzaro, D. Murra, G. Fanti: “Coloring linens withexcimer lasers to simulate the body image of the Turin Shroud” AppliedOptics 47, 1278-1283 (Optical Society of America, 2008).

• P. Di Lazzaro, D. Murra, A. Santoni, G. Fanti, E. Nichelatti, G. Baldacchini:“Deep Ultraviolet radiation simulates the Turin Shroud image” Journal ofDeep Ultraviolet radiation simulates the Turin Shroud image Journal ofImaging Science and Technology 54, 040302-(6) (Imaging.org 2010).

• D. Murra, P. Di Lazzaro: “Sight and brain, an introduction to the visuallyg ymisleading images”, International Workshop on the Scientific approach tothe Acheiropoietos Images, edited by P. Di Lazzaro (ENEA 2010) pp. 31 - 34.

• P Di Lazzaro D Murra A Santoni E Nichelatti G Baldacchini:• P. Di Lazzaro, D. Murra, A. Santoni, E. Nichelatti, G. Baldacchini:“Superficial and Shroud-like coloration of linen by short laser pulses inthe vacuum ultraviolet” Applied Optics 51, 8567-8578 (Optical Society ofA i 2012)America, 2012).

• P. Di Lazzaro, D. Murra, B. Schwortz: “Pattern recognition after imageprocessing of low-contrast images, the case of the Shroud of Turin”processing of low contrast images, the case of the Shroud of TurinPattern Recognition 46, 1964-1970 (Elsevier, 2013).


atsi bari, 5 september 2014 - enea · atsi bari, 5 september 2014 shroudshroud--like coloration,...

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