[GIS] Remove unused nodes from OSM data files

openstreetmap

For some experiments on OSM data size, I am using osmfilter to remove ways and relations with certain tags from the planet dump. But AFAIK osmfilter does not remove the corresponding nodes. So I'm left with a huge number of nodes that are not used by anything, and that distort my data size results.

Is there a tool to remove unused nodes (those that have no tags and are not referenced by either a way or a relation) from OSM data files (e.g. .pbf or .osm.bz2 files)?

Best Answer

You could drop all the data (--drop-*) and keep only the bits you're interested in (--keep-*)

Cfr http://wiki.openstreetmap.org/wiki/Osmfilter#Drop_all_Nodes.2C_Ways_or_Relations

You can also try with osmosis http://wiki.openstreetmap.org/wiki/Osmosis/Detailed_Usage

Related Solutions

[GIS] creating vector layer from OSM file using OpenLayers

OpenLayers OSM protocol does not know about 'visible' nodea, but you could easily extend the base class methods with a little bit of code that checks for the visibile attribute before adding the node to the list of nodes like the following (I hope your javascript-fu is strong, alsoe beware that this is untested code so it could not run right the first time):

    //Initialise the vector layer using OpenLayers.Format.OSM
    var pois_layer = new OpenLayers.Layer.Vector("Brussels POIs", {
        strategies: [new OpenLayers.Strategy.Fixed()],
        protocol: new OpenLayers.Protocol.HTTP({
            url: "brussels_center_filtered.osm",   
            format: new OpenLayers.Format.OSM({
                getNodes: function(doc) {
                        var node_list = doc.getElementsByTagName("node");
                        var nodes = {};
                        for (var i = 0; i < node_list.length; i++) {
                            var node = node_list[i];
                            if(node.getAttribute("visible")) {
                                var id = node.getAttribute("id");
                                nodes[id] = {
                                    'lat': node.getAttribute("lat"),
                                    'lon': node.getAttribute("lon"),
                                    'node': node
                                };
                            }
                        }
                        return nodes;
                    },
            })
            }),
            projection: new OpenLayers.Projection("EPSG:4326")
        });

[GIS] Extracting nodes and edges from osm data

You can find some MATLAB scripts to import openstreetmap files here: http://www.mathworks.com/matlabcentral/fileexchange/35819-openstreetmap-functions these include functions for plotting the map and network, as well as a routing example.

Best Answer

Related Solutions

[GIS] creating vector layer from OSM file using OpenLayers

[GIS] Extracting nodes and edges from osm data

Related Question