CVPR - Dec. 2001 Scene-Consistent Detection of Feature Points in Video Sequences Ariel Tankus & Yehezkel Yeshurun Tel-Aviv University Outline: Relating convexity-based detection of feature points to scene geometry. Feature points tracking algorithm. Comparison with two other methods.
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.
Ariel Tankus & Yehezkel Yeshurun
Robust detection of scene-consistent features in video sequences.
Detect convex or concave image domains.
Detect local “circles” where the gradient of the intensity function points outward along the whole circle.
The gradient points in all orientations along the “circles”.
deriveOperator for Extracting Certain Gradient Orientations
At the discontinuity ray of the arctan: Yarg.
Darg - An isotropic variant of Yarg.
The basic observation:
Response of Y has a jump discontinuity there.arg to theIntensity Surface (cont.)
The cases include: Some configurations where
is a local extrema of , and
some configurations where one side of
is flat, but the other is convex or concave.
Only specific differential geometry structures of the intensity function causes Yarg.
#28 has a jump discontinuity there.
#200 has a jump discontinuity there.
#5 has a jump discontinuity there.
Time(correct 3D point is tracked) has a jump discontinuity there.
Completeness of track T =
Time(correct 3D point appears in video)Measures for Evaluation of Scene-Consistency
Correct 3D point of track T =
3D point tracked for the longest time under track T
Stability of tracking in frames f has a jump discontinuity there.i, fi+1 =
#tracks following the correct 3D point in both fi, fi+1
#tracks containing points in both fi, fi+1
Measures for Evaluation of Scene-Consistency (cont.)
Completeness: has a jump discontinuity there.