anis Purpose This function performs the calculation of Anisotropy metric using the method of Periodograms. Synopsis [y, r] = anis(x, d) [y, r] = anis(x, d, f) [y, r] = anis(x, d, f, s) [y, r, c] = anis(x, d) [y, r, c] = anis(x, d, f) [y, r, c] = anis(x, d, f, s) Description [y, r] = anis(x, d) calculates the Anisotropy metric, y of type double, for input image x of type double, using periodograms of dims. given by the matrix d. d = [M N] or d = [N] (for square periodograms). It also returns the radial frequency array r of type double. [y, r] = rapsd(x, d, f) calculates the Anisotropy metric, 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, r] = rapsd(x, d, f, s) calculates the Anisotropy metric, 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, r, c] = rapsd(x, d) [y, r, c] = rapsd(x, d, f) [y, r, c] = rapsd(x, d, f, s) calculates the Anisotropy metric, 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 psd2, rapsd, hxpsd2, hxrapsd, hxanis Reference [1] R. A. Ulichney, Digital Halftoning, MIT Press, Cambridge, Mass., 1987 Author Faraz Faheem, Dated: 10/23/99. Dr. Daniel L. Lau, Dated: 04/20/04. 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 4/20/04