Patent Document ID: 20020150303
Application ID: 09788615
Patent Status: 0

Claim One:
1. A spatial filtering method comprising the steps of: (a) acquiring a digital image comprising a two-dimensional array of pixel data from an original image; (b) calculating a first Fourier Transform of the digital image to generate a two-dimensional array of complex data from the equation: 5 F &it; ( u, v ) = 1 / N &it; &Sum; x = 0 N - 1 &it; &it; &Sum; y = 0 N - 1 &it; f &it; ( x, y ) &it; &ee; - 2 &it; πj &af; ( ux + vy ) ; (c) calculating a power spectrum to provide a real function representing a weighting of each spatial frequency in the two-dimensional array of complex data calculated in step (b) from the equation: P ( u,v )&equals;log (1 &plus;F ( u,v ) F *( u,v )); (d) generating a mask for suppressing periodic structures of the original image and undesirable artifacts introduced by the acquiring of the digital image in step (a); (e) dilating the mask generated in step (d) by extending masking spots generated therein to increase suppression of periodic structures of the original image; (f) applying the mask dilated in step (e) to remove the periodic data from the first Fourier transform resulting from step (b) to result in a second set of complex data corresponding to a second Fourier transform; (g) calculating an inverse Fourier transform using the second set of complex data corresponding to the second Fourier transform of the digital image masked in step (f) to obtain a spatially filtered original image from the equation: 6 f &it; ( x, y ) = 1 / N &it; &Sum; u = 0 N - 1 &it; &it; &Sum; v = 0 N - 1 &it; &it; F &it; ( u, v ) &it; &ee; + 2 &it; πj &af; ( ux + vy ) ; (h) scaling the spatially filtered image to greyscale; and (i) providing a visual representation of the greyscaled image obtained in step (h).