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We seek correspondence and transformation that make corresponding attributes match. Such transformation should obey geometric constraints. Alignment based on local correspondences can fail: attributes at corresponding locations do not match under deformation. 5.Experiments on ETHZ Dataset Qualitative Results Quantitative Results (Contour) Contour Segment Challenge x y μ x y μ (b) Object Matching under pose variation Edge Orientation Attribute “Attribute Flow” suggests object transformation Color Attribute (a) Object matching under deformation Given bottom-up salient contours and segments, we want to detect the object, align the shape densely and extracted foreground segmentation in a one shot fashion. x y μ ::: x y μ ::: Oriented Edge Attribute (c) Intra-Category Object Matching 1.Goal Image with contours/ segments Shape Model Input Detection Shape Alignment Foreground Segmentation Output 2.Attribute Flow Discriminative Image Warping using Attribute Flow Weiyu Zhang, Praveen Srinivasan, and Jianbo Shi Finding Attribute Histogram Matching Matching using Ground Distance Rotation: :Image :Model Minimizing ground distance fails under object rotation. Model Mass Preservation during matching. Attribute Histogram Flow Finding Image Transformation Model Image 3.Affine Constraint on Attribute Flow = Color Histogram Oriented Edge Ground distance + Affine Ground distance only Soft Spatial Affine Constraint Soft Orientation Affine Constraint Soft Affine Constraint on Ground Distance : Euclidian distance an attribute travels till matching ) ( = Attribute Flow x Finding Attribute Mapping Oriented Edge Attribute. : number of edge orientation. Each Attribute is bind to one image location . Canonical Model Space Warping: Selected Warped Contour Model Space Warping reduces pose variation. Learning in model space requires fewer training examples, also picks up smaller but distinctive features 4.Constrained Attribute Flow w/ Selection Constrained Histogram Flow: Challenge: Previous approaches on image alignment assume pre-segmented objects. We do not have this assumption and still need to select which attributes that participate in the matching, and which ones are assigned to background. Selected Image Contour Solving this in a brute force fashion is expensive since it requires synthesizing attributes for each transformation . Optical Flow Translation: 0.6 0.4 0.1 1.3 1.1 0.6 0.8 1 Model Hist. Image Hist. Respect contour integrity. Contour Selection (Zhu et al., ECCV 2008) 0 1 0 1 1 0 Input Image with Clutter Shape Model :Constrained Bin : Anchor Bin Solve Attribute Flow w/ selection Model Histogram Deformed Model Histogram Selected Image Contour Affine Constraint on Image Transformation Spatial Constraint: Preserve barycentric coordinates of all attributes’ locations w.r.t anchor points. Orientation Constraint: Preserve barycentric coordinates of unit vectors of all oriented attribute (e.g. edge orientation) w.r.t. anchor points. Constrained Points Anchor Points Unit Vector Marginalize to get using Expectations can be viewed as a probability encoding of the transformation. Marginalize over spatial overlapping bins to get local translation. Take expectation over to get local orientation transformation.
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Weiyu Zhang, Praveen Srinivasan, and Jianbo Shijshi/papers/CVPR2011_poster... · 2011. 6. 16. · Weiyu Zhang, Praveen Srinivasan, and Jianbo Shi Affine Constraint on Optical Flow

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Page 1: Weiyu Zhang, Praveen Srinivasan, and Jianbo Shijshi/papers/CVPR2011_poster... · 2011. 6. 16. · Weiyu Zhang, Praveen Srinivasan, and Jianbo Shi Affine Constraint on Optical Flow

We seek correspondence

and transformation that

make corresponding

attributes match. Such

transformation should obey

geometric constraints.

Alignment based on local

correspondences can fail:

attributes at corresponding

locations do not match under

deformation.

TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: AAAAAAAAAAAA

5.Experiments on ETHZ Dataset

Qualitative Results

Quantitative Results (Contour)

Co

nto

ur

Seg

me

nt

Challenge

x

x

(b) Object Matching under pose variation

Edge Orientation Attribute

“Attribute Flow” suggests object transformation

Color

Attribute

(a) Object matching under deformation

Input Given bottom-up salient contours and segments, we want to detect the object, align the shape densely and extracted foreground segmentation in a one shot fashion.

x

: : :x

: : :

Oriented Edge Attribute

(c) Intra-Category Object Matching

1.Goal

Image with contours/ segments

Shape Model

Input

Detection

Shape Alignment

Foreground Segmentation

Output

2.Attribute Flow

Discriminative Image Warping using Attribute Flow Weiyu Zhang, Praveen Srinivasan, and Jianbo Shi

Affine Constraint on Optical Flow T

Barycentric

Coordinate

Preservatio

n

F can be viewed as Probability encoding of T

Finding Attribute Histogram Matching Matching using

Ground Distance

Rotation:

:Image :Model Minimizing ground distance

fails under object rotation. Model Mass Preservation during matching.

Attribute Histogram Flow

Finding Image

Transformation

Model Image

3.Affine Constraint on Attribute Flow

6=

Color

Histogram

Oriented

Edge Ground

distance

+ Affine

Ground

distance

only

Soft Spatial Affine Constraint

Soft Orientation Affine Constraint

Soft Affine Constraint on

Ground

Distance :

Euclidian

distance an

attribute travels

till matching

)(=

Attribute Flow

x

Finding Attribute Mapping

Oriented Edge Attribute. : number of edge orientation.

Each Attribute is bind to one image location .

Canonical

Model

Space

Warping: Selected

Warped Contour

Model Space Warping reduces pose

variation. Learning in

model space requires

fewer training examples,

also picks up smaller but

distinctive features

4.Constrained Attribute Flow w/ Selection Constrained Histogram Flow:

Challenge: Previous approaches on image alignment assume

pre-segmented objects. We do not have this assumption and

still need to select which attributes that participate in the

matching, and which ones are assigned to background.

Selected

Image Contour

Solving this in a brute force fashion is

expensive since it requires synthesizing

attributes for each transformation .

Optical Flow

Translation:

0.6 0.4

0.1

1.3

1.1

0.6

0.8

1

Model

Hist.

Image

Hist.

Respect contour integrity.

Contour Selection (Zhu et al., ECCV 2008)

010110

Input Image with Clutter

Shape Model

:Constrained Bin

: Anchor Bin

Solve

Attribute Flow w/ selection

Model Histogram

Deformed Model Histogram

Selected Image Contour

Affine Constraint on Image Transformation

Spatial

Constraint:

Preserve barycentric coordinates of all attributes’

locations w.r.t anchor points.

Orientation

Constraint: Preserve barycentric coordinates of unit vectors of all

oriented attribute (e.g. edge orientation) w.r.t. anchor points.

Constrained

Points

Anchor

Points

Unit

Vector

Marginalize to get using Expectations

can be viewed as a probability

encoding of the transformation.

Marginalize over

spatial overlapping bins

to get local translation.

Take expectation over

to get local orientation

transformation.