psd2 Purpose This function performs the Power Spectral Density Estimation using the method of Periodograms. Synopsis y = psd2(x, d) y = psd2(x, d, f) y = psd2(x, d, f, s) [y, c] = psd2(x, d) [y, c] = psd2(x, d, f) [y, c] = psd2(x, d, f, s) Description y = psd2(x, d) calculates the power spectral density estimate, y of type double, for input image x of type double, using a periodogram of dimensions given by the matrix d. d = [M N] or d = [N] (for square periodograms). y = psd2(x, d, f) calculates the power spectral density estimate, y of type double, for input image x of type double. f is the frequency domain matrix dimensions, holding the results of the fft of periodogram. It's dimensions cannot be smaller than d. f = [FM FN] or f = [FN]. If f is not specified or f = [0], then f = d. y = psd2(x, d, f, s) calculates the power spectral density estimate, y of type double, for input image x of type double. s is a matrix holding the shift parameters i.e. the amount by which the sample window (periodogram) must be shifted for the next sample. s = [SM SN] or s = [SM]. If s is not specified or s = [0], then s = d. [y, c] = psd2(x, d) [y, c] = psd2(x, d, f) [y, c] = psd2(x, d, f, s) calculates the power spectral density estimate, y of type double, for input image x of type double and also returns the count c of the sample windows (periodograms) for the calculation of sample variance. See Also rapsd, anis, hxpsd2, hxrapsd, hxanis Reference [1] R. A. Ulichney, Digital Halftoning, MIT Press, Cambridge, Mass., 1987 Author Faraz Faheem, Dated: 10/23/99. Daniel L. Lau, Dated: 04/16/04 Dr. Daniel Leo Lau Department of Electrical and Computer Engineering University of Kentucky 453 Anderson Hall Lexington, KY 40506-0046, USA (859) 257-2300 x273 dllau@engr.uky.edu last edited on 4/16/04