| 摘要 |
A method for compressing a string of characters, initially defined by an original ordered sequence of characters each represented by an absolute number uniquely representing each character, according to an absolute coding table, comprising the steps of: parsing said original sequence into at least one first type subsequence comprising contiguous characters, each of the contiguous characters of the first type sub-sequence being selected based on a matching character in a relative coding table (20), and, into at least one second type sub-sequence comprising remaining contiguous characters, coding each first type sub-sequence using said relative coding table (20), representing each character from each second type sub-sequence by its absolute representing number from said absolute coding table. A corresponding method for decompressing a compressed sequence. |
| 主权项 |
1. A method for compressing a string of characters, initially defined by an original ordered sequence of characters each represented by an absolute number uniquely representing each character, according to an absolute coding table, comprising:
parsing said original sequence into at least one first type sub-sequence comprising contiguous characters, each of the contiguous characters of the first type sub-sequence matching a corresponding character in a relative coding table, and into at least one second type sub-sequence comprising contiguous remaining characters, coding each first type sub-sequence using said relative coding table, copying each character from each second type sub-sequence in said compressed sequence, each character being represented by its absolute representing number from said absolute coding tablewherein the coding of a first type sub-sequence comprises:
coding the initial character of said sub-sequence by its original absolute representing number from said absolute coding table, as a keycode, coding each character following said initial character in said sub-sequence by coding a displacement in said relative coding table, between a character preceding said character and said character, ending the coding of said first type sub-sequence by coding a displacement toward a second specific control character in said relative coding table, indicative of an end of coding, after the last character in said sub-sequence,wherein the coding of a displacement in said relative coding table, between a preceding character and a following character, comprises:
determining a first coordinate, separating, in said relative coding table, said preceding character from said following character, along a first predetermined direction, determining a second coordinate, separating, in said relative coding table, said preceding character from said following character, along a second predetermined direction, concatenating all determined coordinates, in order, into the compressed sequence,wherein said first coordinates are chosen in a first set of numbers and said second coordinates are chosen in a second set of numbers, wherein no number is shared between said first set of numbers and said second set of numbers, and wherein one first particular coordinate among said first set, and one second particular coordinate among said second set, are omitted in the compressed sequence, except when two particular coordinates are immediately following, in which case said following particular coordinate is not omitted. |
