HOG Trilinear Interpolation of Histogram Bins

Question

I am working on Histogram of Oriented Gradient(HOG) features and I am trying to implement the trilinear interpolation of histogram bins as described in Dalal\'s PhD thesis.

Answer 1

Lets first look at rectangular HOG. A picture is divided into a few tiles as shown on page 32. Page 46 shows an R-HOG descriptor in (f). Page 49 explains how the data is binned.

I learned how to do 3D interpolation by reading Paul Burke's write-up: http://paulbourke.net/miscellaneous/interpolation/

Sorry, I would have to generate my own images, in order to understand what is going on. It is certainly an interesting technique.