Patent ID: 8290282

Claim:
A method for reducing the size of a digital file comprising at least one of compressed or uncompressed digital values, wherein the digital values are encoded in an original brightness scale from 0 to 255 for each color layer, comprising: converting successive values of an original file into successive original groups of values, each group being identified by an original median value of values in the successive original group of values, replacing the original median values by reduced brightness coding values within a predetermined reduced brightness scale smaller than the original brightness scale, replacing each coding value by a reproduced group having values equal to the original median value corresponding to said coding value, modifying a plurality of successive redundant reproduced values to output a plurality of modified values, depending on how many successive redundant values are contained in each group of reproduced values, according to the following rules: if a redundant value appears two times, add âˆ’2 and 0 to the successive redundant values to obtain the plurality of modified values, if a redundant value appears three times, add âˆ’2, 0 and +2 to the successive redundant values to obtain the plurality of modified values, if a redundant value appears four times, add âˆ’2, âˆ’1, 0, and +2 to the successive redundant values to obtain the plurality of modified values, if a redundant value appears five times, add âˆ’2, âˆ’1,0, +1 and +2 to the successive redundant values to obtain the plurality of modified values, andâ€”, reading the obtained plurality of modified values.