R ECONSTRUCTION ON S MOOTH M ANIFOLDS Bhuwan Dhingra Dual Degree Student Electrical Engineering IIT Kanpur
I NTRODUCTION A lot of high-dimensional datasets lie on or near a smooth low-dimensional manifold Ex: Disk Images Each image lies on a 2-dimensional manifold in a 100x100x3 space
D IMENSION R EDUCTION Non-Linear methods (ISOMAP, LLE etc.) find a low-dimensional embedding of the sampled points on the manifold Out-of-Sample reconstruction – construct the high-dimensional images for new test points, given the training point images
L OCAL L INEAR I NTERPOLATION Specifically, can we improve over simple linear interpolation in a local neighborhood on the manifold? Linear interpolation: Find k -nearest neighbors of new point Minimize Reconstruction
T ANGENT S PACE P ARAMETERIZATION (T YAGI, V URAL AND F ROSSARD )
T ANGENT S PACE R ECONSTRUCTION
T ANGENT S PACE E STIMATION
L INEAR R EGRESSION ON T ANGENT S PACE Red circle shows the interpolated test point on the tangent space
Q UADRATIC R EGRESSION ON H IGHER C OMPONENTS
T ANGENT S PACE V L INEAR R ECONSTRUCTION Actual Data Tangent Space Linear
V IDEO F RAME I NTERPOLATION Foreman video sequence ISOMAP used to embed into m = 1 dimensional space
T HANK Y OU