Patent ID: 6246802
Filing Date: 2001-06-12
Classification: G06T,H04N

Abstract:
An image data processor which supplies data obtained by:applying an orthogonal conversion to an original image so as to convert it to a spatial frequency area data set,modifying said spatial frequency data by adding n second spatial frequency data calculated from one set of n predetermined identifying data w(1), w(2), . . . w(n) and n spatial frequency data f(1), f(2), . . . f(n) selected from said spatial frequency area data set respectively to said spatial frequency data f(1), f(2), . . . f(n), andcompression encoding this modified spatial frequency area data set, said processor comprising:expansion means for expanding said compressed data set,detecting mean for outputting a detection signal when said identifying data is detected from restored values F(i), (i=1, 2, . . . n) of said modified n spatial frequency data f(1), f(2), . . . f(n) obtained from said data set expanded in said expander said detecting means computing a degree of similarity between, firstly, n values F(i)/avg (F(i))(i=1, 2, . . . n), obtained by dividing said restored values by partial averages calculated by partial average calculating means for calculating partial averages avg (F(i))(i=1, 2, . . . n) of said restored values F(i)(i=1, 2, . . . n), and secondly, said identifying data w(i)(i=1, 2, . . . n), and outputs said detection signal when this degree of similarity exceeds a predetermined value,means for applying an inverse orthogonal transformation to said restored spatial frequency area data set so as to restore said original data, andmeans for mixing a signal for causing incorrect operation of an image recording device on which said restored original image is to be recorded when said detecting means outputs said detection signal, and supplying said restored original image to said image recording device when said detection signal is absent.