Patent ID: 6108454
Filing Date: 2000-08-22
Classification: G06T

Abstract:
A method of operating an image sensor, comprising:(a) scanning to produce an image array;(b) applying a one-dimensional discrete Fourier transform (DFT) to each column of said image array to create a DFT array;(c) computing a mean magnitude of each column of said DFT array to create a mean magnitude DFT array;(d) generating a smoothing array having dimensions equal to those of said mean magnitude DFT array;(e) identifying trouble frequencies associated with line contrast difference effect using a least squares error operation on pixels of said mean magnitude DFT array;(f) computing suppression values for each pixel associated with said trouble frequencies using information derived from said least squares error operation;(g) modifying each pixel in said smoothing array corresponding to a pixel in said mean magnitude DFT array associated with said trouble frequencies, based upon a respective one of said suppression values to create a corrected smoothing array;(h) applying said corrected smoothing array to said DFT array on a pixel-by-pixel basis to create a corrected DFT array; and,(i) applying an inverse DFT to said corrected DFT array to reconstruct a corrected version of said image.