Imaging at a trillion frames per second | Ramesh Raskar

Translator: Joseph Geni Reviewer: Thu-Huong Ha

Translator: Irma Sutlic Reviewer: Lenka Tušar

Doc Edgerton inspired us with awe and curiosity

Doc Edgerton je v nas vzbudil čudenje in radovednost

with this photo of a bullet piercing through an apple,

s to sliko izstrelka, ki prodira skozi jabolko

and exposure just a millionth of a second.

pri osvetlitvi milijoninke sekunde.

But now, 50 years later, we can go a million times faster

50 let kasneje smo lahko milijonkrat hitrejši

and see the world not at a million or a billion,

in sveta ne vidimo le pri milijonu

ali milijardi,

but one trillion frames per second.

temveč pri bilijonu sličic na sekundo.

Predstavljam vam novo vrsto fotografije,

I present to you a new type of photography,

femto-photography,

femto-fotografijo,

a new imaging technique so fast

ki je tako hitra tehnika snemanja,

that it can create slow motion videos of light in motion.

da lahko ustvari počasne posnetke gibanja svetlobe.

And with that, we can create cameras that can look around corners,

Izdelamo lahko kamere,

ki lahko pogledajo okrog vogala,

beyond line of sight,

izven zorne linije

or see inside our body without an x-ray,

in brez rentgenskih žarkov vidijo v notranjost telesa

ter izrazu kamera dajejo nov pomen.

and really challenge what we mean by a camera.

Now if I take a laser pointer and turn it on and off

Če vzamem lasersko kazalko in jo vključim

in one trillionth of a second --

za bilijoninko sekunde,

which is several femtoseconds --

kar je nekaj femtosekund,

I'll create a packet of photons barely a millimeter wide.

ustvarim paket fotonov,

ki je širok zgolj milimeter.

And that packet of photons, that bullet,

Ta paket fotonov oziroma izstrelek

will travel at the speed of light,

bo potoval s svetlobno hitrostjo,

and again, a million times faster than an ordinary bullet.

milijonkrat hitreje kot navaden izstrelek.

Now, if you take that bullet and take this packet of photons

Če ta izstrelek oziroma paket fotonov

and fire into this bottle,

izstrelim v plastenko –

how will those photons shatter into this bottle?

kako se bodo fotoni razpršili v plastenki?

How does light look in slow motion?

Kako je videti svetloba v počasnem posnetku?

[Light in Slow Motion ... 10 Billion x Slow]

Now, the whole event --

Celoten dogodek – (Aplavz)

(Applause)

(Aplavz)

Now remember, the whole event is effectively taking place

Torej, celoten dogodek

se odvije v manj kot nanosekundi,

in less than a nanosecond --

that's how much time it takes for light to travel.

kar je čas, ki ga svetloba potrebuje za to pot,

But I'm slowing down in this video by a factor of 10 billion,

vendar je posnetek upočasnjen z večkratnikom 10 milijard,

so you can see the light in motion.

da lahko vidite svetlobo v gibanju.

(Laughter)

But Coca-Cola did not sponsor this research.

Coca-Cola ni sponzor teh raziskav. (Smeh)

(Laughter)

Now, there's a lot going on in this movie,

Na tem posnetku se veliko dogaja,

so let me break this down and show you what's going on.

zato bom opisal korake in vam povedal, za kaj gre.

So the pulse enters the bottle, our bullet,

Utrip svetlobe, naš izstrelek, vstopi v plastenko

with a packet of photons that start traveling through

kot paket fotonov, ki pričnejo svojo pot skozi

and that start scattering inside.

in ki se začnejo v notranjosti sipati.

Some of the light leaks, goes on the table,

Nekaj svetlobe uide ven in gre na mizo,

and you start seeing these ripples of waves.

zato opazite to valovanje.

Many of the photons eventually reach the cap

Kar nekaj fotonov končno doseže pokrovček

and then they explode in various directions.

in jih tam raznese v različne smeri.

As you can see, there's a bubble of air

Vidite lahko zračni mehurček

and it's bouncing around inside.

in kako se v njem odbija.

Meanwhile, the ripples are traveling on the table,

Medtem valovanje potuje po mizi,

and because of the reflections at the top,

zaradi odboja na vrhu

you see at the back of the bottle, after several frames,

pa se na dnu plastenke po nekaj sličicah

odboji osredotočijo.

the reflections are focused.

Če bi vzeli navaden izstrelek,

Now, if you take an ordinary bullet

and let it go the same distance and slow down the video --

ga spustili čez enako razdaljo in posnetek upočasnili

again, by a factor of 10 billion --

prav tako s faktorjem 10 milijard – ali veste,

do you know how long you'll have to sit here to watch that movie?

kako dolgo bi sedeli tu, da bi si ga ogledali?

(Laughter)

A day, a week? Actually, a whole year.

En dan, en teden? Trajalo bi celo leto.

It'll be a very boring movie --

To bi bil zelo dolgočasen posnetek (Smeh)

(Laughter)

of a slow, ordinary bullet in motion.

počasnega, navadnega izstrelka v gibanju.

And what about some still-life photography?

Kaj pa fotografija tihožitja?

You can watch the ripples, again, washing over the table,

Spet lahko vidite valovanje, ki preplavi mizo,

the tomato and the wall in the back.

paradižnik in steno v ozadju.

It's like throwing a stone in a pond of water.

Kot bi v vodo vrgli kamen.

I thought: this is how nature paints a photo,

Narava na tak način naslika fotografijo,

one femto frame at a time,

eno femto sličico za drugo,

but of course our eye sees an integral composite.

a naše oko vidi celovito sestavljeno sliko.

Če še enkrat pogledate paradižnik,

But if you look at this tomato one more time,

you will notice, as the light washes over the tomato,

boste videli, da potem, ko ga preplavi svetloba,

še naprej sije. Ne zatemni se.

it continues to glow.

It doesn't become dark. Why is that?

Zakaj? Paradižnik je dejansko zrel

Because the tomato is actually ripe,

and the light is bouncing around inside the tomato,

in svetloba se znotraj njega odbija,

and it comes out after several trillionths of a second.

ven pa pride po nekaj bilijoninkah sekunde.

So in the future, when this femto-camera is in your camera phone,

Ko boste v prihodnosti to femto-kamero

imeli v svojem mobilnem telefonu,

you might be able to go to a supermarket

boste lahko v trgovini

and check if the fruit is ripe without actually touching it.

preverjali zrelost sadežev ne da bi se jih dotaknili.

(Laughter)

In kako smo z ekipo na MIT izdelali to kamero?

So how did my team at MIT create this camera?

Fotograf ve,

Now, as photographers, you know,

da pri kratki osvetlitvi dobimo le malo svetlobe,

if you take a short exposure photo, you get very little light.

mi pa snemamo pri milijardokrat večji hitrosti

But we're going to go a billion times faster than your shortest exposure,

kot je najkrajša osvetlitev,

so you're going to get hardly any light.

tako da dobimo komaj kaj svetlobe.

So what we do is we send that bullet --

Naredimo tako, da pošljemo izstrelke,

that packet of photons -- millions of times,

te pakete fotonov, milijonkrat

and record again and again with very clever synchronization,

in jih posnamemo znova in znova, jih domiselno uskladimo

and from the gigabytes of data,

in potem iz gigabajtov podatkov,

we computationally weave together

ki jih računsko stkemo skupaj,

to create those femto-videos I showed you.

ustvarimo te femto-posnetke.

Surove podatke zberemo

And we can take all that raw data and treat it in very interesting ways.

in jih obdelamo na zanimive načine.

So, Superman can fly.

Superman lahko poleti.

Some other heroes can become invisible.

Nekateri drugi junaki lahko postanejo nevidni,

But what about a new power for a future superhero:

morda pa bi kak drug super junak lahko

To see around corners.

gledal okrog vogalov?

The idea is that we could shine some light on the door,

Zamisel je v tem, da posvetimo na vrata.

it's going to bounce, go inside the room,

Svetloba se bo odbila v sobo,

some of that is going to reflect back on the door,

nekaj se je bo odbilo nazaj na vrata,

and then back to the camera.

in potem nazaj h kameri,

And we could exploit these multiple bounces of light.

tako da bi lahko izkoristili te večkratne odboje.

And it's not science fiction. We have actually built it.

To ni znanstvena fantastika, to smo res naredili.

On the left, you see our femto-camera.

Na levi vidite femto-kamero.

There's a mannequin hidden behind a wall,

Za steno je skrita lutka,

and we're going to bounce light off the door.

z vrati pa bomo odbili svetlobo.

So after our paper was published in Nature Communications,

Ko je bil naš članek objavljen

v reviji Nature Communications,

it was highlighted by Nature.com,

je nanj opozorila stran Nature.com,

and they created this animation.

kjer so izdelali naslednjo animacijo.

(Music)

(Glasba)

[A laser pulse is fired]

(Music)

Izstrelili bomo izstrelke svetlobe,

Ramesh Raskar: We're going to fire those bullets of light,

and they're going to hit this wall,

ki se bodo zadeli ob to steno,

and because of the packet of the photons,

in ker gre za pakete fotonov,

they will scatter in all the directions,

se bodo ti razpršili v vse smeri,

and some of them will reach our hidden mannequin,

nekaj jih bo doseglo našo skrito lutko,

which in turn will again scatter that light,

ki bo spet razpršila svetlobo,

in potem bodo vrata odbila

and again in turn, the door will reflect some of that scattered light.

nekaj te razpršene svetlobe,

And a tiny fraction of the photons will actually come back to the camera,

majcen del fotonov pa se bo dejansko

vrnil k kameri, vendar – še posebej zanimivo –

but most interestingly,

they will all arrive at a slightly different time slot.

bodo prispeli v različnih časovnih intervalih.

(Music)

(Glasba)

Ker je naša femto-kamera tako hitra,

And because we have a camera that can run so fast --

our femto-camera -- it has some unique abilities.

ima nekaj edinstvenih sposobnosti.

It has very good time resolution,

Ima izredno dobro časovno ločljivost

and it can look at the world at the speed of light.

in svet lahko vidi pri hitrosti svetlobe.

And this way, we know the distances, of course to the door,

Poznamo razdaljo do vrat

but also to the hidden objects,

in do skritih predmetov,

but we don't know which point corresponds to which distance.

ne vemo pa, katera točka ustreza

kateri razdalji.

(Music)

(Glasba)

By shining one laser, we can record one raw photo,

Ko posvetimo z enim laserjem, lahko naredimo en surov posnetek,

which, if you look on the screen, doesn't really make any sense.

ki ni videti prav zgovoren.

But then we will take a lot of such pictures,

Ampak naredimo več takih posnetkov,

na ducate, in jih združimo

dozens of such pictures, put them together,

and try to analyze the multiple bounces of light,

ter analiziramo večkratne odboje svetlobe,

and from that, can we see the hidden object?

iz tega pa – ali lahko vidimo skriti predmet?

Can we see it in full 3D?

Ga lahko vidimo v treh razsežnostih?

So this is our reconstruction.

Takole smo ga rekonstruirali. (Glasba)

(Music)

(Glasba)

(Glasba) (Aplavz)

(Applause)

Še dolga je pot, preden bomo lahko šli

Now, we have some ways to go

before we take this outside the lab on the road,

iz laboratorija v dejansko okolje, a v prihodnosti

but in the future, we could create cars that avoid collisions

bi lahko izdelali avte, ki bi se izogibali trkom

with what's around the bend.

s predmeti izza ovinka,

Or we can look for survivors in hazardous conditions

in v nevarnih okoliščinah bi lahko iskali preživele,

by looking at light reflected through open windows.

s tem, ko bi opazovali svetlobo, odbito prek odprtih oken,

Or we can build endoscopes that can see deep inside the body around occluders,

lahko pa bi izdelali endoskope, ki bi lahko

gledali globoko v telo okrog zapor,

and also for cardioscopes.

ali kardioskope.

But of course, because of tissue and blood,

Seveda bi bilo to zaradi tkiv in krvi

this is quite challenging,

velik izziv, tako da je to poziv

so this is really a call for scientists

znanstvenikom, naj začnejo razmišljati o femtofotografiji

to start thinking about femto-photography

as really a new imaging modality

kot novem načinu snemanja, ki bo rešitev

to solve the next generation of health-imaging problems.

za naslednjo generacijo težav pri zdravstvenih posnetkih.

Now, like Doc Edgerton, a scientist himself,

Enako kot Doc Edgerton, ki je bil tudi znanstvenik,

science became art --

gledam na znanost ultra-hitre fotografije kot na umetnost

an art of ultra-fast photography.

in sem spoznal, da vsi ti gigabajti podatkov,

And I realized

that all the gigabytes of data that we're collecting every time,

ki jih vsakič zberemo,

are not just for scientific imaging.

niso le znanstveni posnetki, ampak lahko izdelamo

But we can also do a new form of computational photography,

novo vrsto računske fotografije

with time-lapse and color coding.

s posnetki v časovnih intervalih in z barvnim označevanjem

And we look at those ripples.

ter z njimi pogledamo valovanje. Ne pozabite,

Remember:

da je časovna razlika med vsakim valom le

The time between each of those ripples is only a few trillionths of a second.

nekaj bilijonink sekunde.

But there's also something funny going on here.

Pri tem pa se dogaja še nekaj čudnega.

Če pogledate valove pod pokrovčkom,

When you look at the ripples under the cap,

the ripples are moving away from us.

vidite, da se oddaljujejo.

Morali pa bi se približevati.

The ripples should be moving towards us.

What's going on here?

Kaj se dogaja?

It turns out, because we're recording nearly at the speed of light,

Zato, ker snemamo

s skoraj svetlobno hitrostjo,

we have strange effects,

dobimo nenavadne učinke –

and Einstein would have loved to see this picture.

Einstein bi najbrž z veseljem videl to sliko.

(Laughter)

The order at which events take place in the world

Zaporedje, po katerem se odvijajo dogodki,

appears in the camera sometimes in reversed order.

so v kameri v navidezno obrnjenem zaporedju,

So by applying the corresponding space and time warp,

ko pa prostor in čas ustrezno upognemo,

we can correct for this distortion.

lahko popačenje popravimo.

So whether it's for photography around corners,

Za vse – fotografijo izza vogala,

zdravstvene posnetke naslednje generacije,

or creating the next generation of health imaging,

or creating new visualizations,

izdelavo novih upodobitev –

smo od odkritja naprej nudili odprto-kodni dostop

since our invention,

we have open-sourced all the data and details on our website,

do vseh podatkov na našem spletnem mestu, in upamo,

and our hope is that the DIY, the creative and the research communities

da bodo domači mojstri, ustvarjalci in raziskovalci

will show us that we should stop obsessing about the megapixels in cameras --

vsem pokazali, naj se nehamo gnati za

megapiksli v kamerah (Smeh)

(Laughter)

and start focusing on the next dimension in imaging.

in naj se obrnemo k naslednji razsežnosti posnetkov.

It's about time.

Nastopil je čas. (Aplavz)

Thank you.

(Applause)

(Aplavz)