Design of a Two Dimensional PRSI Image Processor

A digital processor capable of computing several two dimensional Position Rotation and Scale Invariant (PRSI) transforms on 64 times 64 pixel images is presented. The architecture is programmable to achieve the following five transforms: Two Dimensional (2D) Fast Fourier Transform (FFT), 2D Log Polar Transform (LPT), 2D Fourier Mellin Transform (FMT), 2D Analytical Fourier Mellin Transform and Phase only Correlation (POC). 1D FFT design with scale and word-length issues is also detailed. Thirty two 1-Dimensional FFTs have been reused as processing elements in the 2-Dimensional FFT unit. Scheme for matrix transpose in O(N) time is also described. The Image Processor has a word length of 16 bits each for real and imaginary parts and has been implemented on Xilinx Virtex II FPGA. It is capable of processing an image in less than 0.1 ms.