Lecture 1: Introduction to Biological Vision - Vision Research ...

But V1 cells are that “simple”• Receptive field types– Simple cells• First-order approximation:– linear spatio-temporal filter (i.e. cross-correlation ofimage with weight function) followed by half-waverectificationR i,j (t) = ( W i x,j y L x,y (t))– Complex cells• roughly modeled as (if!) a linear combination ofsimple cells spanning a small region of space,combining a range of phases in the filters (e.g.sine and cosine)x,y• involved in build-up of translation and scaleinvariance for object recognition?W x,ySine phase--”edge detector”Cosine phase--”bar detector”Wednesday, August 29, 12