This method comprises: —accessing (2) a point cloud (PC) comprising a plurality of points defined by attributes, said attributes including a spatial position of a point in a 3D space and at least one feature of the point;—segmenting (2) the point cloud into one or more clusters (Ci) of points on the basis of the attributes of the points; and for at least one cluster (Ci):—constructing (4) a similarity graph having a plurality of vertices and at least one edge, the similarity graph representing a similarity among neighboring points of the cluster (Ci) in terms of the attributes, the plurality of vertices including vertices Pi and Pj corresponding to points of the cluster (Ci);—assigning one or more weights wi,j to one or more edges connecting vertices Pi and Pj of the graph;—computing (6) a transform using the one or more assigned weights, said transform being characterized by coefficients; and—quantizing (8) and encoding (10) the transform coefficients.