Patent ID: 9153029
Filing Date: 2015-10-06
Classification: G01B,G06K

Abstract:
1. A computer-implemented method of determining a two-dimensional position of a location captured in an image, said method comprising: forming a two-dimensional greyscale pattern, said two-dimensional pattern comprising a plurality of R-planes, wherein each said R-plane comprises a tiling of a corresponding R-ary block, being a block of radix R integer values, such that for each dimension of the pattern, the least common multiple of each of the sizes of said corresponding tiled R-ary blocks in that dimension is greater than the size of the pattern in the same dimension, and such that any R-ary sub-block of a predetermined size less than the tiled R-ary blocks occurs only on a regular grid with the same periodicity as the tiled R-ary block for that R-plane; imparting the two-dimensional pattern onto a scene; capturing an image of the scene including the projected two-dimensional pattern; determining from the captured image a sub-block associated with the location and constructing, from a R-ary representation of the sub-block, a unique integer value for each R-plane, being a representation of the pattern in the R-plane of the sub-block associated with the location; and using said unique integer values from each R-plane to determine the location in the image.