Global mapping of the hemi-retinal image into the supragranular layer of the primary visual cortex. This mapping is given in equation 1. Left of figure shows the hemi-retinal field which is mapped to the supragranular layers, shown in the right of figure. The distortion of the hemi-retinal image is shown by black lines. The point f, where the converging black lines meet, is the fovea and has the z coordinates (0,0). The mapping is global, that is, it covers in a single mapping the entire area of V1. The mapping of a set of oriented bar stimuli is shown by coloured rays. Each coloured ray, converging on point g, represents the set of all possible moving, oriented bars which travel along that ray towards point g. A 0^o bar is shown in purple.