An efficient implementation of a phase unwrapping kernel on reconfigurable hardware

The optical quadrature method of microscopy (OQM) uses phase data to capture information about the sample being studied. This phase data need to be unwrapped before it can be of use. Phase unwrapping is the process by which an integer multiple of 2pi is added to a measured, wrapped phase value in order to generate a continuous function. The algorithm used is the minimum L^P norm method which uses a two dimensional discrete cosine transform (2-D DCT) which forms the most computationally expensive part of the minimum L^P norm method. This paper presents an implementation on reconfigurable hardware that performs the 2-D DCT over the entire 1024 times 512 image, solves the intermediate equation and then performs the two dimensional Inverse discrete cosine transform (2-D IDCT) using a novel FPGA implementation of the DCT with a semi-floating point data representation. This represents the largest 2-D DCT FPGA implementation in the literature, with most previous work focusing on the 8 times 8 transform.