3d layoutcrf derek hoiem carsten rother john winn

3D LayoutCRF

Derek Hoiem

Carsten Rother

John Winn

2

Goal 1: Object Description

Object Description:

• Bounding Box

• Viewpoint

• Color

• Pose

• Subclass

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Goal 2: Object Segmentation

4

• Combine object-level and pixel-level reasoning

Key Idea

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Recognition Requires Object-Level Reasoning

• Position

• Shape/Size

• Viewpoint/Pose

• Style/Color

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Recognition Requires Object-Level Reasoning

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Solution: Window Detector?

• 45 degree range of viewpoints

• Minor scale/position variation

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What if we have a really good model?

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Recognition Requires Part-Level Reasoning

• Propose good global model

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Recognition Requires Part-Level Reasoning

• Propose good global model

• Occlusions

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Context Requires Both Object and Part-Level Info

• Size relationships require object model

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Context Requires Both Object and Part-Level Info

• Surface relationships require occlusion info

Visibly sitting on ground

Not visibly sitting on ground

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Our Object/Part Model

Ti = {

hj object parts

bounding box, viewpoint, color model, instance cost }

part consistency

occlusions

Tm

h1 h2 h3 h4

h5 h6 h7 h8

h9 h10 h11 hn

x

…

…

Extension from [Winn Shotton 2006]

T1…

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Modeling Viewpoint

Parameterized by Bounding Box and Corner

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Assigning Parts from Model

Training Image

FL

Training Annotation

Assigned Parts3D Parts Model

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Part Assignment Consistency

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Relabeling

• Allowing slight deformations, relabel training data

Training Image

Original Labels

New Labels

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Eight Viewpoint/Scale Ranges

Height Range

• Appearance (but not location) constant within each range

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Modeling Part Appearance

• Template patches (normalized xcorr)

• Intensity / Color

Image Edges (DT)

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Modeling Part Appearance

• Randomized decision trees– 25 trees, 250 leaf nodes

• Once:– Learn structure on 50,000 object / 50,000 background

pixels

• For each appearance model:– Learn parameters on all pixels (850 LabelMe images)

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Inference

Input Image

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Inference

Input Image

Proposals

• One per appearance model

• Objects proposed by connected components

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Proposal Stage Model

hi object parts

part consistency

occlusions

h1 h2 h3 h4

h5 h6 h7 h8

h9 h10 h11 hn

x

…

…

• CRF Inference (TRW-BP)

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Inference

Refinement

• One per proposal

• Incorporate viewpoint, size information

Proposals

Input Image

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Refinement Stage Model

Ti = {

hi object parts

bounding box, viewpoint }

part consistency

occlusions

T1

h1 h2 h3 h4

h5 h6 h7 h8

h9 h10 h11 hn

x

…

…

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Inference

Refinement

Proposals

Arbitration

• Includes color model, instance penalty (graph cuts)

Input Image

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Preliminary Results on UIUC

• Trained on 20, tested on rest• Quantitatively comparable to best

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Preliminary Results on UIUC

Without Instance Cost

With Instance Cost

T1

h1 h2 h3 h4

h5 h6 h7 h8

h9 h10 h11 hn

x

…

…

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Preliminary Results on PASCAL’06

• 25 images– One proposal (viewpoint within 45 degrees,

scale of 26-38 pixels)

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Preliminary Results on PASCAL’06

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Preliminary Results on PASCAL’06

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Preliminary Results on PASCAL’06

Without Color Model

With Color Model

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Conclusion

• Combined object-level and pixel-level reasoning – Object-level: Position/Size, Viewpoint, Color– Pixel-level: Part appearance, Occlusion

reasoning

• Good preliminary results