18. The apparatus according to claim 13 , further comprising machine readable instructions to: determine a transformation that corrects a perspective distortion of a regular grid hypothesis; apply the determined transformation to the surface coded pattern; and apply one or more criteria to the transformed surface coded pattern to generate a measure of validity of the regular grid hypothesis.
18. The apparatus according to claim 13 , further comprising machine readable instructions to: determine a transformation that corrects a perspective distortion of a regular grid hypothesis; apply the determined transformation to the surface coded pattern; and apply one or more criteria to the transformed surface coded pattern to generate a measure of validity of the regular grid hypothesis. 19. The apparatus according to claim 18 , wherein the applied criteria comprises at least one of: a proportion of regular grid points to a total points of the surface coded pattern is greater than a predetermined threshold value; an average number of data carrying pattern points interleaved within the regular grid points is within a predetermined range; and a number of regular grid cells formed by the regular grid hypothesis is above a predetermined value.