Process for producing synthetic video images for real time visual display and high information density and apparatus using this process

Claim 1

A process for producing a real time visual display of the element of the image, called fast or slow symbols and constituting a synthetic video image having a high information density, said process comprising: generating synthetic video signals corresponding to said symbols; storing said synthetic video signal in a memory having at least one image plane; reading of said memory for display of said stored synthetic video image; distinguishing between the symbols which present practically no change and have a fixed and substantially low evolution and denominating these symbols as slow symbols and the other symbols of the image which evolve faster and denominating these symbols as fast symbols; determining, with respect to said distinguishment between said slow and fast symbols, a subdivision of the image and consequently a subdivision of the memory into zones and respectively attributing thereto a periodic refreshing rate, in accordance with the distinctive evolution of the symbols therein; said zones and refreshing rates being determined according to said respective evolution of said symbols wherein each zone has a periodic refreshing rate selected from between at least one each image display cycle for the symbols of fixed or slow evolution and a maximum number of n times each cycle for the symbols of fast evolution; matching said rate according to the evolution characteristics of the symbols included in the zone considered so that the integral refreshing of the image is obtained every n cycles, facilitating the writing of the memory during each image display cycle by selective refreshing, while maintaining a real time display; and varying the dimensions of each zone and their respective refreshing frequencies as a function of the evolution of symbols included in said zone.