A Special-Purpose Processor for FFT-Based Digital Refocusing using 4-D Light Field Data

In this paper, we use a pinhole-array-mask light field camera to generate duplicated spectra in the frequency domain. Based on Fourier-Slicing Theorem, we can collect light field information on different image planes by taking different data-slices in the frequency domain. When a series of sliced data is converted back to the spatial domain, digital-refocusing can be performed. Since the digital refocusing process is time-consuming, we design a special-purpose processor for acceleration. The chip is synthesized with TSMC 90nm technology. A 15X speedup can be achieved when compared to the software version.