Methods for the compression and decompression of a digital terrain model file; associated compressed and decompressed files and associated computer program product

Abstract

Method for compressing a digital terrain model file including a tile including a matrix of cells, each cell including an elevation value for a geographical point of the terrain, by representing the tile in the form of an initial tree having a plurality of depth levels, each terminal node of the initial tree representing a zone of the tile corresponding to a single cell, pruning the initial tree so as to obtain a pruned tree, encoding the elevation value associated with each of the terminal nodes of the pruned tree to obtain a differential elevation value starting from a reference elevation, and serializing the pruned tree resulting from the encoding to obtain a compressed file indicating the reference elevation, followed by a plurality of sequences, each sequence including a header and a load, indicative of a depth level and a differential elevation value of a terminal node, respectively.