Method of encoding and decoding a graphics path sequence into a layered scheme

摘要

This invention relates to a method of encoding a path (1) in layered form so as to allow partial decoding and progressive rendering while decoding. The path (1) is made of an original sequence (20, 23) of original draw commands, each corresponding to an original portion of a drawing. The method of encoding comprises the following steps:
- transforming (E120, E230, E430, E440, E450) at least one original draw command into an approximating draw command according to a geometrical approximation of the corresponding original portion of a drawing, to obtain a reduced sequence (25);
- encoding (E130, E250) said reduced sequence (25) into an encoded reduced sequence; and
- encoding (E150, E260) a reconstruction information set (26) representing the difference between the reduced sequence (25) and the original sequence (20, 23). The invention is particularly suitable for graphics description languages, such as SVG.