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 ). <EOS>