How computers learn to recognize objects instantly | Joseph Redmon

1,121,269 views

2017-08-18 ・ TED


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How computers learn to recognize objects instantly | Joseph Redmon

1,121,269 views ・ 2017-08-18

TED


Dvaput kliknite na engleske titlove ispod za reprodukciju videozapisa.

Prevoditelj: Ivan Nekić Recezent: Sanda L
00:12
Ten years ago,
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Prije deset godina,
00:13
computer vision researchers thought that getting a computer
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istraživači računalnog vida mislili su da je naučiti računalo
00:16
to tell the difference between a cat and a dog
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kako razlikovati između mačke i psa
00:19
would be almost impossible,
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gotovo nemoguće,
00:21
even with the significant advance in the state of artificial intelligence.
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čak i uz značajan napredak u razvoju umjetne inteligencije.
00:25
Now we can do it at a level greater than 99 percent accuracy.
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Sad to možemo učiniti s više od 99 posto točnosti.
00:29
This is called image classification --
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To se zove klasifikacija slike -
00:31
give it an image, put a label to that image --
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dati sliku, staviti oznaku na sliku -
00:34
and computers know thousands of other categories as well.
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a računala znaju i tisuće drugih kategorija.
00:38
I'm a graduate student at the University of Washington,
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Ja sam postdiplomac na Sveučilištu u Washingtonu
00:41
and I work on a project called Darknet,
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i radim na projektu pod nazivom Darknet,
00:43
which is a neural network framework
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što je neuronska mrežna struktura
00:45
for training and testing computer vision models.
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za obuku i testiranje modela računalnog vida.
00:47
So let's just see what Darknet thinks
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Pa pogledajmo što Darknet misli
00:50
of this image that we have.
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o ovoj slici koju imamo.
00:54
When we run our classifier
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Kad smo pokrenuti naš klasifikator
00:56
on this image,
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na ovoj slici,
00:57
we see we don't just get a prediction of dog or cat,
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ne dobivamo samo predviđanja je li to pas ili mačka,
01:00
we actually get specific breed predictions.
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nego čak i određena predviđanja pasmine.
01:02
That's the level of granularity we have now.
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To je razina zrnatosti koju imamo sada.
01:04
And it's correct.
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I to je točno.
01:06
My dog is in fact a malamute.
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Moj pas je doista malamut.
01:08
So we've made amazing strides in image classification,
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Napravili smo nevjerojatne pomake u klasifikaciji slike,
01:13
but what happens when we run our classifier
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ali što se događa kad pokrenemo klasifikator
01:15
on an image that looks like this?
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na sliku koja izgleda ovako?
01:18
Well ...
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Dobro ...
01:24
We see that the classifier comes back with a pretty similar prediction.
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Vidimo da je klasifikator vraća uz prilično slična predviđanja.
01:28
And it's correct, there is a malamute in the image,
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I to je točno, na slici je malamut,
01:31
but just given this label, we don't actually know that much
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ali samo s tom oznakom ne znamo mnogo
01:35
about what's going on in the image.
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o tome što se događa na slici.
01:36
We need something more powerful.
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Trebamo nešto snažnije.
01:39
I work on a problem called object detection,
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Radim na problemu koji se zove otkrivanje objekta,
01:41
where we look at an image and try to find all of the objects,
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gdje gledamo sliku i pokušavamo pronaći sve objekte,
01:44
put bounding boxes around them
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staviti okvire oko njih
01:46
and say what those objects are.
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i reći ono što ti predmeti su.
01:48
So here's what happens when we run a detector on this image.
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Evo što se događa kad pokrenemo detektor na ovoj slici.
01:53
Now, with this kind of result,
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Ovakvom vrstom rezultata
01:55
we can do a lot more with our computer vision algorithms.
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možemo napraviti puno više s algoritmima računalnog vida.
01:58
We see that it knows that there's a cat and a dog.
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Vidimo da zna da su tu mačka i pas.
02:01
It knows their relative locations,
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Zna njihove relativne položaje,
02:03
their size.
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njihovu veličinu.
02:04
It may even know some extra information.
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Čak može znati neke dodatne informacije.
02:06
There's a book sitting in the background.
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U pozadini je knjiga.
02:09
And if you want to build a system on top of computer vision,
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Ako želite izgraditi sustav na osnovi računalnog vida,
02:12
say a self-driving vehicle or a robotic system,
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recimo autonomno vozilo ili robotski sustav,
02:15
this is the kind of information that you want.
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ovo je vrsta informacija koje želite.
02:18
You want something so that you can interact with the physical world.
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Želite nešto da možete komunicirati s fizičkim svijetom.
02:22
Now, when I started working on object detection,
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Kad sam počeo raditi na prepoznavanju objekata,
02:24
it took 20 seconds to process a single image.
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trebalo je 20 sekundi za obradu jedne slike.
02:28
And to get a feel for why speed is so important in this domain,
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A kako biste dobili osjećaj zašto je brzina ovdje tako važna,
02:32
here's an example of an object detector
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evo primjera detektora objekta
02:35
that takes two seconds to process an image.
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koji treba dvije sekunde za obradu slike.
02:37
So this is 10 times faster
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Dakle ovo je 10 puta brže
02:40
than the 20-seconds-per-image detector,
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od detektora kojem treba 20 sekundi po slici,
02:44
and you can see that by the time it makes predictions,
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i možete vidjeti da se za vrijeme dok on učini predviđanja,
02:46
the entire state of the world has changed,
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promijenilo čitavo stanje u svijetu,
02:49
and this wouldn't be very useful
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i to ne bi bilo vrlo korisno
02:52
for an application.
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za neku primjenu.
02:53
If we speed this up by another factor of 10,
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Ako ovo gore ubrzamo još jednom za faktor 10,
02:56
this is a detector running at five frames per second.
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to je detektor koji radi na pet sličica u sekundi.
02:58
This is a lot better,
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To je puno bolje,
03:00
but for example,
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ali, na primjer,
03:02
if there's any significant movement,
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ako postoji bilo kakav značajan pokret,
03:04
I wouldn't want a system like this driving my car.
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ne bih želio da sustav poput ovog vozi moj auto.
03:08
This is our detection system running in real time on my laptop.
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Ovo je naš sustav otkrivanja u realnom vremenu na mom laptopu.
03:12
So it smoothly tracks me as I move around the frame,
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Glatko me prati kako se krećem kroz kadar,
03:15
and it's robust to a wide variety of changes in size,
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i otporan je na razne promjene veličine,
03:21
pose,
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položaja,
03:23
forward, backward.
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naprijed, natrag.
03:24
This is great.
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Ovo je super.
03:26
This is what we really need
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To je ono što stvarno trebamo
03:27
if we're going to build systems on top of computer vision.
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ako ćemo graditi sustave na osnovi računalnog vida,
03:30
(Applause)
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(Pljesak)
03:36
So in just a few years,
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U samo nekoliko godina
03:38
we've gone from 20 seconds per image
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došli smo od 20 sekundi po slici
03:40
to 20 milliseconds per image, a thousand times faster.
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do 20 milisekundi po slici, tisuću puta brže.
03:44
How did we get there?
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Kako smo došli dovde?
03:45
Well, in the past, object detection systems
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Nekada su sustavi za otkrivanje predmeta
03:49
would take an image like this
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uzimali sliku poput ove
03:50
and split it into a bunch of regions
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i podijelili je na hrpu područja
03:53
and then run a classifier on each of these regions,
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i zatim pokrenuli klasifikator na svakom od tih područja.
03:56
and high scores for that classifier
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Visoki rezultati za taj klasifikator
03:59
would be considered detections in the image.
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smatrali su se detekcijom u slici.
04:02
But this involved running a classifier thousands of times over an image,
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No, to je značilo rad klasifikatora tisuće puta na slici,
04:06
thousands of neural network evaluations to produce detection.
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tisuće procjena neuronskih mreža kako bi dobili detekciju.
04:11
Instead, we trained a single network to do all of detection for us.
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Umjesto toga smo naučili jednu mrežu da učini sve detekcije za nas.
04:15
It produces all of the bounding boxes and class probabilities simultaneously.
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Ona istodobno proizvodi sve okvire i klase vjerojatnosti.
04:20
With our system, instead of looking at an image thousands of times
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S našim sustavom, umjesto da gledate sliku tisuće puta
04:24
to produce detection,
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kako bi postigao detekciju,
04:25
you only look once,
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gledate samo jednom,
04:26
and that's why we call it the YOLO method of object detection.
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zato ga zovemo YOLO metoda za detekciju objekta.
04:31
So with this speed, we're not just limited to images;
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Dakle, ovom brzinom nismo ograničeni samo na slike;
04:35
we can process video in real time.
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možemo obraditi video u realnom vremenu.
04:37
And now, instead of just seeing that cat and dog,
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Sad, umjesto da samo vidimo mačku i psa,
04:40
we can see them move around and interact with each other.
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vidimo kako se kreću i međusobno komuniciraju.
04:46
This is a detector that we trained
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To je detektor koji smo obučili
04:48
on 80 different classes
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na 80 različitih klasa
04:52
in Microsoft's COCO dataset.
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u Microsoftovoj zbirci podataka COCO.
04:56
It has all sorts of things like spoon and fork, bowl,
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Ona ima svašta, poput žlice i vilice, zdjele,
04:59
common objects like that.
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obične predmete poput tih.
05:02
It has a variety of more exotic things:
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Ima raznih egzotičnijih stvari:
05:05
animals, cars, zebras, giraffes.
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životinje, automobili, zebre, žirafe.
05:08
And now we're going to do something fun.
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A sada idemo učiniti nešto zabavno.
05:10
We're just going to go out into the audience
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Samo ćemo otići u publiku
05:12
and see what kind of things we can detect.
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i vidjeti što možemo otkriti.
05:14
Does anyone want a stuffed animal?
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Želi li tko plišanu životinju?
05:17
There are some teddy bears out there.
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Tamo ima nekih medvjedića.
05:21
And we can turn down our threshold for detection a little bit,
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Možemo malo smanjiti prag detekcije,
05:26
so we can find more of you guys out in the audience.
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tako da možemo naći više vas u publici.
05:31
Let's see if we can get these stop signs.
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Da vidimo možemo li dobiti ove znakove STOP.
05:33
We find some backpacks.
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Nalazimo neke ruksake.
05:37
Let's just zoom in a little bit.
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Zumirajmo samo malo.
05:42
And this is great.
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I to je super.
05:43
And all of the processing is happening in real time
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Sva obrada se događa u stvarnom vremenu
05:46
on the laptop.
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na laptopu.
05:48
And it's important to remember
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I to je važno zapamtiti
05:50
that this is a general purpose object detection system,
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da je ovo sustav za detekciju objekta opće namjene,
05:53
so we can train this for any image domain.
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možemo ga trenirati za bilo koju domenu.
06:00
The same code that we use
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Isti kod koji koristimo
06:02
to find stop signs or pedestrians,
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za pronaći znakove STOP ili pješake,
06:05
bicycles in a self-driving vehicle,
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bicikle u autonomnim vozilima,
06:07
can be used to find cancer cells
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može se koristiti kako bi pronašli stanice raka
06:10
in a tissue biopsy.
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u biopsiji tkiva.
06:13
And there are researchers around the globe already using this technology
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A znanstvenici diljem svijeta već koriste ovu tehnologiju
06:18
for advances in things like medicine, robotics.
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za napredak u medicini, robotici.
06:21
This morning, I read a paper
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Jutros sam pročitao članak
06:22
where they were taking a census of animals in Nairobi National Park
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o popisu životinja u Nacionalnom parku Nairobi
06:27
with YOLO as part of this detection system.
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koristeći YOLO u sustavu detekcije.
06:30
And that's because Darknet is open source
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A to je zato što je Darknet open source,
06:33
and in the public domain, free for anyone to use.
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u javnoj domeni, besplatan svakomu za korištenje.
06:37
(Applause)
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(Pljesak)
06:43
But we wanted to make detection even more accessible and usable,
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No, željeli smo napraviti detekciju još dostupnijom i korisnijom
06:48
so through a combination of model optimization,
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pa smo kombinacijom optimizacije modela,
06:52
network binarization and approximation,
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binarizacije mreže i aproksimacije
06:54
we actually have object detection running on a phone.
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dobili detekciju objekata koja radi na mobitelu.
07:04
(Applause)
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(Pljesak)
07:10
And I'm really excited because now we have a pretty powerful solution
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A ja sam stvarno uzbuđen jer sada imamo moćno rješenje
07:15
to this low-level computer vision problem,
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problema računalnog vida na osnovnoj razini,
07:18
and anyone can take it and build something with it.
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i svatko ga može uzeti i graditi nešto njime.
07:22
So now the rest is up to all of you
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Sad je sve ostalo do vas
07:25
and people around the world with access to this software,
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i ljudi diljem svijeta s pristupom tom softveru,
07:28
and I can't wait to see what people will build with this technology.
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jedva čekam vidjeti što će ljudi učiniti s ovom tehnologijom.
07:31
Thank you.
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Hvala vam.
07:33
(Applause)
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(Pljesak)
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