geometric blur descriptors for point correspondence
DESCRIPTION
Geometric Blur Descriptors for Point Correspondence. Nisarg Vyas Computational Photography (15862) Final Project, Carnegie Mellon University. Motivation. Point Correspondences are used in many vision applications Image Alignment - PowerPoint PPT PresentationTRANSCRIPT
Geometric Blur Descriptors for Point Correspondence
Nisarg VyasComputational Photography
(15862) Final Project,
Carnegie Mellon University
Motivation
Point Correspondences are used in many vision applications Image Alignment 3D reconstruction of scene from multiple views Object Recognition Vehicle path Navigation Structure from Motion
Point Correspondence
Basic Approaches: SSD, NCC
,Do not work well under affine transfoms
Blurred Descriptors
MOPS
Geometric Blur
Geometric Blur: Introduction
A “Spatially varying” Kernel which smoothes
Instead of Kx(y) = Gσ(y), Kx(y) = Gα|x|(y)
Comparison: Geometric Blur & Gaussian Blur
Geometric Blur “Descriptor”
Take signed Gradient of input image in both directions, we will now be with 4 channels
Geometric Blur “Descriptor”Take a feature point, calculate Blur Descriptor for all 4 gradient channels,Subsampled in concentric circles
Results
Results
Results
Status so far & Plans for final submission Done implementing Geometric Blur
Descriptor Results are not as good as expected,
sometimes simple SSD does even better !! Have to try changing the thresholds which
varies the sigma Trying Other interesting descriptors
(SIFT,C1), If time permits
References
[1] Geometric Blur for Template Matching A.C. Berg and J. Malik, CVPR, 2001[2] Shape Matching and Object Recognition
using Low-distortion Correspondences, A.C. Berg, T.L. Berg and J. Malik, CVPR,
2005[3] Comparing Visual Features for Morphing
Based Recognition, J.J. Wu, MIT CSAIL Technical report, 2005 (TR-2005-035)
Questions and Suggestions?