Abstract: A method and apparatus for assessing the visibility of differences between two input signal sequences, e.g., image sequences is disclosed. The apparatus comprises a perceptual metric generator having an input signal processing section, a luminance processing section, a chrominance processing section and a perceptual metric generating section.

Abstract: An improved color picture tube includes a screen and an inline gun for generating and directing three inline electron beams along separate paths toward the screen. The electron gun includes electrodes that provide a beam-forming region, a prefocus region and a main focus region. The beam-forming region of the gun includes a cathode, a G1 electrode, a G2 electrode and a first portion of a G3 electrode. The prefocus region includes a second portion of the G3 electrode, a G4 electrode and a first portion of a G5 electrode. The main focus region includes a second portion of the G5 electrode and a G6 electrode. The improvement resides in the beam-forming region, the prefocus region and the main focus region each being astigmatic.