Patent ID: 7319755

Claim:
An image altering apparatus for providing confidential viewing of a fundamental display image by a viewer, comprising: a. a display comprised of a plurality of pixels; b. means for generating a fundamental image on said display, said fundamental image having at least one color component corresponding to each of said pixels; c. means for modifying said fundamental image to generate a compound image which is substantially featureless, said compound image including at least one compound color component corresponding to each of said pixels; d. each said compound color component being comprised of at least one said color component of a predetermined intensity and wavelength, time multiplexed with at least one corresponding inverse color component of the same said wavelength, wherein each said inverse color component has an intensity which is determined as a function of said corresponding color component, such that the time-weighted average of said intensities of all said color components and said corresponding inverse color components thereof is substantially the same for each said compound color component of said compound image; e. means for extracting said fundamental image from said compound image for viewing only by the viewer.