TU Wien:Computer Vision VU (Sablatnig)/Prüfung 2019-03-08

90 Minuten Zeit, nur eine Gruppe, Taschenrechner für letzte Frage erforderlich

Camera True/False Kreuzerl (-1 Point for wrong answers)

• In contrast to lenses the pinhole camera projects an orthographic image
• Perspective Projection is a non-linear transform
• Parallel lines remain parallel in perspective projection
• Camera measures part of plenoptic function
• Focal length is a extrinsic camera parameter
• Texture is a depth cue

Machine Learning

• Supervised vs. Unsupervised
• Generalization
• Gradient Descent

Harris

Describe how constructed

Gaussian

• Describe what is Gaussian Pyramid and how is it constructed
• Describe how Laplacian Pyramid can be constructed from

SIFT

• Describe how Sift is made scale-invariant?
• Is vl_dsift scale-invariant, argument why?

Epilar Definitions

• Baseline
• Epipol
• Epipolar line
• Disparity
• Fundamental Matrix

Stereo True/False Kreuzerl (-1 Point for wrong answers)

• In Structure-from-Motion the location of the 3D Scene Point and the Camera Point is calculated
• BRDF is given per material
• A Trifocal-Tensor is a relationship between 3 views of the scene
• With P given the 3D Scene Point can be reconstructed
• Disparity is a binocular depth cue
• Essential Matrix is 3x3

Bag of Words

• How is codeword dictionary generated?
• What is representation of image for classification?

Gabor

• What are Gabor Wavelets?
• What is the Real and Imaginary Component?

RANSAC

• 300 correct matchings in 500 features, what is the probability of drawing 4 inliers?
• How many runs are necessary to construct a correct homography with 99% confidence.
• Why is it good to construct the final homography from all inliers of the best run?