- 60 Views
- Uploaded on
- Presentation posted in: General

Out-of-plane Rotations

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

2

1

3

- Environment constraints
- Surveillance systems
- Car driver images

- ASM:
- Similarity does not remove 3D pose
- Multiple-view database

- Other approaches
- Non-linear models
- 3D models: multiple views

AV@CAR Database

Geometric operations by means of linear algebra

2D points are 3-component vectors

Multiple views of the same planar object can be related by homographies

2

1

3

1

2

3

4

2

1

3

- Homographies hold both for object or camera movements
- The points must be coplanar

H

2

1

3

- Silhouette points are excluded (out of main plane)
- Half the nose points are excluded (easy occlusion)
- First iteration: At least 8 correspondences to compute H (4 2D-points)

Model Coordinates

Image Coordinates

ASM Image Model (Similarity)

Gradient normal to the shape contour

Projective transformations

Do not preserve angles nor distance relationships

2

1

3

H

2

1

3

2

1

3

ASM

- Training and test on multi-view data
- Cross validation

PASM

2

1

3

Ratios with respect to error on frontal images

2

1

3

- Training set: Frontal
- Test set: Multilple views

2

1

3

2

1

3

- If multi-view dataset available
- Almost invariant to rotations up to 60 degrees

- Training only on frontal views
- Considerably reduces (50%) variation of ASM due to viewpoint

- Left-right rotations better handled than up-down nodding
- Very difficult to compare to other results
- Points used for alignment can affect performance
- Not considerable for expected ASM precision

2

1

4

3