Patent ID: 8838442

Claim:
A method of transforming a first spectrum having few non-zero values into a spectrum having a large number of non-zero values, the sparse spectrum including a number N of points lying in a plane, the method comprising: defining, by a processor-based device, a rotation angle for rotating successive pairs of points of the first spectrum, wherein the rotation angle is between π/4 and π/2, the processor-based device being executed on a computer having a non-transitory computer readable medium storing a plurality of instructions executable by one or more processors; applying, by the processor-based device, a first rotation operation using the rotation angle on a first set of successive pairs of points, wherein members of each pair of points of the first set of successive pairs of points are separated by a first stride length; and applying, by the processor-based device, a second rotation operation using a second rotation angle on a different set of successive pairs of points, wherein members of each pair of points of the different set of successive pairs of points are separated by a second stride length.