mit6870_orsu_lecture6: scenes and objects
TRANSCRIPT
![Page 1: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/1.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 1/104
Lecture 6Scenes and objects
6.870 Object Recognition and Scene Understandinghttp://people.csail.mit.edu/torralba/courses/6.870/6.870.recognition.htm
![Page 2: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/2.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 2/104
Class business
Next Wednesday«
![Page 3: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/3.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 3/104
Week 2: Objects without scenes
Week 5: Scenes without objects
Week 6: Scenes and objects
![Page 4: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/4.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 4/104
Why is detection hard?
x
y
1,000,000 images/dayPlus, we want to do this for ~ 1000 objects
10,000 patches/object/image
time
![Page 5: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/5.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 5/104
Standard approach to scene analysis
1) Object representation based on intrinsic features:
Local
featuresno car
Classifier
p( car | VL )
2) Detection strategy:
Sky
Mountain
Buildings
cars
3) The scene representation
![Page 6: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/6.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 6/104
Is local information enough?
![Page 7: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/7.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 7/104
With hundreds of categories
roadtablechair
keyboardtablecar
road
If we have 1000 categories (detectors), and each detector produces 1 fa every 10
images, we will have 100 false alarms per image« pretty much garbage«
![Page 8: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/8.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 8/104
Is local information even enough?
![Page 9: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/9.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 9/104
Is local information even enough?
Distance
Information
Local featuresContextual features
![Page 10: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/10.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 10/104
We know there is a keyboard present in this scene even if we cannot see it clearly.
We know there is no keyboard present in this scene
« even if there is one indeed.
The system does not care about the
scene, but we do«
![Page 11: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/11.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 11/104
The multiple personalities of a blob
![Page 12: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/12.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 12/104
The multiple personalities of a blob
![Page 13: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/13.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 13/104
![Page 14: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/14.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 14/104
![Page 15: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/15.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 15/104
![Page 16: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/16.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 16/104
Look-Alikes by Joan Steiner
![Page 17: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/17.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 17/104
Look-Alikes by Joan Steiner
![Page 18: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/18.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 18/104
Look-Alikes by Joan Steiner
![Page 19: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/19.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 19/104
Why is context important?
Changes the interpretation of an object (or its function)
Context defines what an unexpected event is
![Page 20: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/20.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 20/104
The influence of an object extends beyond its physical boundaries
![Page 21: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/21.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 21/104
The context challenge
How far can you go withoutusing an object detector?
![Page 22: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/22.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 22/104
21
What are the hidden objects?
![Page 23: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/23.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 23/104
What are the hidden objects?
Chance ~ 1/30000
![Page 24: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/24.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 24/104
![Page 25: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/25.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 25/104
The importance of context
Cognitive psychology ± Palmer 1975
± Biederman 1981
± «
Computer vision ± Noton and Stark (1971)
± Hanson and Riseman (1978)
± Barrow & Tenenbaum (1978) ± Ohta, kanade, Skai (1978)
± Haralick (1983)
± Strat and Fischler (1991)
± Bobick and Pinhanez (1995)
± Campbell et al (1997)
![Page 26: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/26.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 26/104
Biederman 1972
Arrow appeared before or after picture.
Selected object from 4 pictures.
![Page 27: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/27.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 27/104
![Page 28: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/28.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 28/104
![Page 29: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/29.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 29/104
Biederman 1972
Better accuracy with normal scene and
with pre-cue.
C
oherence of surroundings affected objectperception.
But, jumbled pictures had unnatural edge
artifacts.
![Page 30: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/30.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 30/104
Palmer 1975
Scene preceded object to identify.
Better identification when preceded by a
semantically consistent scene.
Objects seen for 20, 40, 60 or 120 ms.
![Page 31: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/31.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 31/104
Palmer
Scenes shown ahead of time for 2 s.
More accurate recognition of consistent
objects than inconsistent objects. Similar looking objects were misnamed,
showing a bias effect.
![Page 32: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/32.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 32/104
Loftus & Mackworth
Inconsistent objects
fixated earlier and
longer.
Suggested additional
processing of objects
out of context. Similar results found
by Friedman (1979).
![Page 33: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/33.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 33/104
De Graef et al. 1990
Prior results due to memory task?
Measured eye movements during non-
object search task.
![Page 34: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/34.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 34/104
![Page 35: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/35.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 35/104
Object Detection
Biederman et al. 1982, relational violations
![Page 36: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/36.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 36/104
![Page 37: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/37.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 37/104
Biederman 1982
Pictures shown for 150
ms.
Objects in appropriate
context were detected
more accurately than
objects in aninappropriate context.
Scene consistency
affects object detection.
![Page 38: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/38.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 38/104
Objects and Scenes
Biederman¶s violations (1981):
![Page 39: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/39.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 39/104
Support
[Golconde Rene Magritte]
![Page 40: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/40.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 40/104
Interposition
[Blank Check Rene Magritte]
![Page 41: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/41.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 41/104
![Page 42: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/42.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 42/104
Position, Probability
[P ersonal Values Rene Magritte]
![Page 43: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/43.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 43/104
Object Consistencies
Biederman et al (1982), DeGraef(1990).
![Page 44: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/44.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 44/104
Object Consistencies
Examples of inconsistencies
Biederman et al (1982), DeGraef(1990).
![Page 45: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/45.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 45/104
Contextual cueing
Chun & Jiang, 1998
![Page 46: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/46.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 46/104
Object priming
Torralba, Sinha, Oliva, VSS 2001
Increasing contextual information
![Page 47: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/47.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 47/104
Object priming
Torralba, Sinha, Oliva, VSS 2001
bj i i
![Page 48: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/48.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 48/104
?Car, pedestrian, mailbox, «
Object priming
p(object | scene)
Torralba, Sinha, Oliva, VSS 2001
Obj i i
![Page 49: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/49.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 49/104
Object priming
Torralba, Sinha, Oliva, VSS 2001
![Page 50: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/50.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 50/104
Ex amples of consistent scenes (a), inconsistent scenes (b), and isolated objects and
backgrounds (c); from Davenport & P otter, 2004
![Page 51: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/51.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 51/104
But do we really need context?
![Page 52: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/52.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 52/104
Hollingworth & Henderson
Concerns with object detection studies
± Object label could bias results.
± Location cue selectively helpful for consistent
objects.
Controlled for false alarm biases with post-
cue and 2AFC.
Failed to find consistency effects.
![Page 53: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/53.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 53/104
Hollingworth & Henderson
Post-cue
2AFC with object
labels
± Both consistent or
inconsistent.
2AFC with tokendiscrimination.
± E.g. sports car or
sedan.
![Page 54: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/54.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 54/104
![Page 55: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/55.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 55/104
![Page 56: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/56.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 56/104
![Page 57: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/57.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 57/104
![Page 58: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/58.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 58/104
CONDOR systemStrat and Fischler (1991)
Guzman (S EE ), 1968
Noton and Stark 1971
Hansen & Riseman (VI S ION S ), 1978
Barrow & Tenenbaum 1978
Brooks ( ACRONYM ), 1979
Marr, 1982
Ohta & Kanade, 1978
Yakimovsky & Feldman, 1973
A A f S U d di
![Page 59: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/59.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 59/104
An Age of Scene Understanding
Guzman (S EE ), 1968 Noton and Stark 1971
Hansen & Riseman(VI S ION S ), 1978
Barrow & Tenenbaum 1978
Brooks ( ACRONYM ), 1979
Marr, 1982
Ohta & Kanade, 1978
Yakimovsky & Feldman, 1973
[Ohta & Kanade 1978]
C
![Page 60: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/60.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 60/104
Current approaches
1) Scene to object dependencies
2) Object to object dependencies
L l f
![Page 61: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/61.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 61/104
Levels of context
Context in low-level vision
Part-based models
Objects relations Long-range connections
Weak constraints
Multimodal
Fix graph structurescan be useful
approximations
C t h
![Page 62: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/62.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 62/104
Current approaches
1) Scene to object dependencies
2) Object to object dependencies
![Page 63: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/63.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 63/104
b t this co occ rrence has a hidden
![Page 64: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/64.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 64/104
« but this co-occurrence has a hidden
common ³cause´: the scene
streetsoffices
It is easier to first recognize the scene, then predict object presence, than
running local object classifiers
Th l d t t f
![Page 65: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/65.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 65/104
The layered structure of scenes
In a display with multiple targets present, the location of one target constraints the µy¶
coordinate of the remaining targets, but not the µx¶ coordinate.
Assuming a human observer standing on the ground
![Page 66: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/66.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 66/104
D t ti f ith t f d t t
![Page 67: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/67.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 67/104
Detecting faces without a face detector
Torralba & Sinha, 01; Torralba, 03
Context based vision system for place
![Page 68: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/68.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 68/104
Context-based vision system for place
and object recognition
Hidden states = location (63 values) Observations = vG
t (80 dimensions)
Transition matrix encodes topology of
environment Observation model is a mixture of
Gaussians centered on prototypes (100
views per place)
Office 610 Corridor 6b Corridor 6c Office 617
We use 17 annotated sequences for training
Torralba, Murphy, Freeman and Rubin. ICCV 2003
O bil i
![Page 69: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/69.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 69/104
Our mobile rig
Torralba, Murphy, Freeman, Rubin. 2003
![Page 70: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/70.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 70/104
![Page 71: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/71.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 71/104
![Page 72: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/72.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 72/104
![Page 73: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/73.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 73/104
An integrated model of Scenes
![Page 74: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/74.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 74/104
An integrated model of Scenes,
Objects, and Parts
Ncar
S
g
Scene
Scene
gist
features
0
0
1
1
5
5
N
P(Ncar | S = street)
P(Ncar | S = park)
0 5 10 1 50
0 .0 5
0. 1
0 .1 5
0. 2
0 5 1 0 1 50
0. 2
0. 4
0. 6
0. 8
N
![Page 75: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/75.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 75/104
Global to local
![Page 76: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/76.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 76/104
Global to local
Use global context to predict objects but there is nomodeling of spatial relationships between objects.
Op1,c1
vp1,c1
OpN,c1
vpN,c1. . .
Op1,c2
vp1,c2
OpN,c2
vpN,c2. . .
Class 1 Class 2
E1 E2
S
c2maxVc1
maxV
X1X2
vg
Keyboards
Murphy, Torralba & Freeman (03)
3d Scene Context
![Page 77: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/77.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 77/104
3d Scene Context
Image World
Hoiem, Efros, Hebert ICCV 2005
3d Scene Context
![Page 78: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/78.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 78/104
3d Scene Context
meters
m e t e
r s
Ped
Ped
Car
Hoiem, Efros, Hebert ICCV 2005
3D City Modeling using Cognitive Loops
![Page 79: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/79.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 79/104
3D City Modeling using Cognitive Loops
N.C
ornelis, B. Leibe, K.C
ornelis, L.V
an Gool.CV
PR'06
Current approaches
![Page 80: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/80.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 80/104
Current approaches
1) Scene to object dependencies
2)O
bject to object dependencies
Where should I put the silverware?
![Page 81: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/81.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 81/104
Where should I put the silverware?
Sampling from the labels
![Page 82: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/82.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 82/104
Sampling from the labels
Sampling from the labels
![Page 83: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/83.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 83/104
Sampling from the labels
Cf. Hoiem et al; Hays, Efros. Siggraph 2007
Contextual object relationships
![Page 84: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/84.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 84/104
Contextual object relationshipsCarbonetto, de Freitas & Barnard (2004) Kumar, Hebert (2005)
Torralba Murphy Freeman (2004)
Fink & Perona (2003)E. Sudderth et al (2005)
Object-Object Relationships
![Page 85: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/85.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 85/104
Fink & Perona (NIPS 03)Use output of boosting from other objects at previous
iterations as input into boosting for this iteration
Object-Object Relationships
Pixel labeling using MRFs
![Page 86: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/86.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 86/104
Pixel labeling using MRFs
Enforce consistency between neighboring
labels, and between labels and pixels
Carbonetto, de Freitas & Barnard, ECCV¶04
Beyond nearest-neighbor grids
![Page 87: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/87.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 87/104
Beyond nearest-neighbor grids
Most MRF/C
RF models assume nearest-neighbor graph topology
This cannot capture long-distance
correlations
Dynamically structured trees
![Page 88: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/88.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 88/104
Dynamically structured trees
Each node pick its parents(Storkey& Williams, PAMI¶03)
2D SCFGs(Pollak, Siskind, Harper & Bouman IC ASSP¶03)
Object-Object Relationships
![Page 89: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/89.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 89/104
Object Object Relationships
Use latent variables to induce long distance correlations
between labels in a Conditional Random Field (CRF)
He, Zemel & Carreira-Perpinan (04)
Object-Object Relationships
![Page 90: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/90.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 90/104
Object-Object Relationships
[Kumar Hebert 2005]
Hierarchical Sharing and Context
![Page 91: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/91.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 91/104
Hierarchical Sharing and Context
Scenes share objects
Objects share parts
Parts share features
E. Sudderth, A. Torralba, W. T. Freeman, and A. Wilsky.
3d Scene Context
![Page 92: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/92.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 92/104
3d Scene Context
Image Support Vertical Sky
V-Left V-Center V-Right V-Porous V-Solid
[Hoiem, Efros, Hebert ICCV 2005]
Object
Surface?
Support?
Detecting difficult objects
![Page 93: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/93.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 93/104
Detecting difficult objects
Office Maybethere is
a mouse
Start recognizing the scene
Torralba, Murphy, Freeman. NIPS 2004.
![Page 94: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/94.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 94/104
Detecting difficult objects
![Page 95: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/95.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 95/104
Detecting difficult objects
Detect first simple objects (reliable detectors) that provide strong
contextual constraints to the target (screen -> keyboard -> mouse)
Torralba, Murphy, Freeman. NIPS 2004.
BRF for screen/keyboard/mouse
![Page 96: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/96.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 96/104
BRF for screen/keyboard/mouse
Iteration
BRF for screen/keyboard/mouse
![Page 97: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/97.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 97/104
BRF for screen/keyboard/mouse
Iteration
BRF for screen/keyboard/mouse
![Page 98: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/98.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 98/104
BRF for screen/keyboard/mouse
Iteration
BRF for screen/keyboard/mouse
![Page 99: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/99.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 99/104
BRF for screen/keyboard/mouse
Iteration
BRF for screen/keyboard/mouse
![Page 100: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/100.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 100/104
BRF for screen/keyboard/mouse
Iteration
BRF for car detection: topology
![Page 101: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/101.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 101/104
BRF for car detection: topology
BRF for car detection: results
![Page 102: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/102.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 102/104
BRF for car detection: results
A ³car´ out of context is less of a car
![Page 103: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/103.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 103/104
A car out of context is less of a car
Car Building Road
b F G b F G b F G
From image
From detectors
Thresholded beliefs
![Page 104: MIT6870_ORSU_lecture6: Scenes and objects](https://reader035.vdocuments.mx/reader035/viewer/2022062600/577d221b1a28ab4e1e96961b/html5/thumbnails/104.jpg)
8/3/2019 MIT6870_ORSU_lecture6: Scenes and objects
http://slidepdf.com/reader/full/mit6870orsulecture6-scenes-and-objects 104/104
Contextor no context