Fast progressive reconstruction of a transformed image (Corresp.)

Fast methods for performing progressive reconstruction of Fourier and Hadamard transformed images have been developed. Reconstruction of anN times Npoint transformed image can be evaluated in orderN^{2} log_{2} Ninstructions. Accumulation of round-off errors due to iteration is reduced by the factor(log_{2} N + 1) / N^{2}, compared with direct evaluation of the inverse transform.