Method for encoding the borders of pixel regions of an image, wherein the borders contain a sequence of vertices subdividing the image into regions of pixels, called superpixels, by generating a sequence of symbols from an alphabet comprising: - defining for each superpixel a first vertex for coding the borders of said superpixel according to a criterion common to all superpixels; - defining for each superpixel the same coding order of the border vertices, either clockwise or counter-clockwise; - defining the order for coding the superpixels on the base of a common rule depending on the relative positions of said first vertices; - defining a set of vertices as a known border (R b), wherein the following steps are performed for selecting a symbol of the alphabet, for encoding the borders of the superpixels: a) determining the first vertex of the next superpixel border individuated by said common criterion; b) determining the next vertex to be encoded on the basis of said coding direction; c) selecting a first symbol ("0") for encoding said next vertex if the next vertex of a border pertains to said known border (R b), d) selecting a symbol ("1"; "2") different from said first symbol ("0") if the next vertex is not in said known border (R b) e) repeating steps b), c), d) until all vertices of the superpixel border have been encoded; f) adding each vertex of the superpixel border that was not in said known border (R b) to said set; g) determining the next superpixel whose border is to be encoded according to said common rule, if any; i) repeating steps a)-g) until the borders of all the superpixels of the image have been added to said known border (R b). - defining for each superpixel a first vertex for coding the borders of said superpixel according to a criterion common to all superpixels; - defining for each superpixel the same coding order of the border vertices, either clockwise or counter-clockwise; - defining the order for coding the superpixels on the base of a common rule depending on the relative positions of said first vertices; - defining a set of vertices as a known border (R b), wherein the following steps are performed for selecting a symbol of the alphabet, for encoding the borders of the superpixels: a) determining the first vertex of the next superpixel border individuated by said common criterion; b) determining the next vertex to be encoded on the basis of said coding direction; c) selecting a first symbol ("0") for encoding said next vertex if the next vertex of a border pertains to said known border (R b), d) selecting a symbol ("1"; "2") different from said first symbol ("0") if the next vertex is not in said known border (R b) e) repeating steps b), c), d) until all vertices of the superpixel border have been encoded; f) adding each vertex of the superpixel border that was not in said known border (R b) to said set; g) determining the next superpixel whose border is to be encoded according to said common rule, if any; i) repeating steps a)-g) until the borders of all the superpixels of the image have been added to said known border (R b). a) determining the first vertex of the next superpixel border individuated by said common criterion; b) determining the next vertex to be encoded on the basis of said coding direction; c) selecting a first symbol ("0") for encoding said next vertex if the next vertex of a border pertains to said known border (R b), d) selecting a symbol ("1"; "2") different from said first symbol ("0") if the next vertex is not in said known border (R b) e) repeating steps b), c), d) until all vertices of the superpixel border have been encoded; f) adding each vertex of the superpixel border that was not in said known border (R b) to said set; g) determining the next superpixel whose border is to be encoded according to said common rule, if any; i) repeating steps a)-g) until the borders of all the superpixels of the image have been added to said known border (R b).