Cameras

Importer les données avec OSM2PGSQL

local cameras = osm2pgsql.define_node_table('cameras', {
    { column = 'id', sql_type = 'serial', create_only = true },
    { column = 'geom', type = 'point' },
})

local highways = osm2pgsql.define_way_table('highways', {
    { column = 'id', sql_type = 'serial', create_only = true },
    { column = 'geom', type = 'linestring' },
})

local buildings = osm2pgsql.define_area_table('buildings', {
    { column = 'id', sql_type = 'serial', create_only = true },
    { column = 'geom', type = 'polygon' },
})

function osm2pgsql.process_node(object)
    if object.tags.man_made == 'surveillance' then
        cameras:insert({
            geom = object:as_point( )
        })
    end
end

function osm2pgsql.process_way(object)
    if object.is_closed and object.tags.building then
        buildings:insert({
            geom = object:as_polygon()
        })
    end

    if object.tags.highway then
        highways:insert({
            geom = object:as_linestring()
        })
    end
end

function osm2pgsql.process_relation(object)
    if object.tags.type == 'multipolygon' and object.tags.building then
        local geom = object:as_multipolygon()

        for g in geom:geometries() do
            buildings:insert({
                geom = g,
            })
        end

    end
end

osm2pgsql -d toto -U toto -W -H localhost -O flex -S extarct_features.lua st_quentin.osm.pbf

Utiliser postgis

Calculer une distance

with c1 as (select geom as g from cameras where id = 1), c2 as (select geom as g from cameras where id = 2) select ST_Distance(c1.g, c2.g) from c1, c2 ;

calculer les ways qui sont a moins de 100m d'une camera

select c.node_id, h.way_id from cameras c left join highways h on ST_DWithin(c.geom, h.geom, 100) where c.id = 1

Calculer les ways visible d'une camera

create view visible_streets_from_cam as
with
    fields as (
        select
            c.node_id as camera_id,
            h.way_id as street_id,
            -- Changer ici pour la résolution du test d'intersection
            ST_Segmentize(h.geom, 2) as street_geom,
            c.geom as camera_coord
        from
            cameras c
        left join
            -- Changer ici pour la distance à la caméra
            highways h on ST_DWithin(c.geom, h.geom, 100)
        --where c.node_id = 9760071131
    ),
    segments as (
        select
            camera_id,
            street_id,
            ST_MakeLine(camera_coord,p) as seg_line,
            seg_id
        from (
            select
                fields.camera_id,
                fields.street_id,
                fields.camera_coord,
                generate_series(1, ST_NPoints(fields.street_geom)) as seg_id,
                ST_PointN(fields.street_geom, generate_series(1, ST_NPoints(fields.street_geom))) as p
            from fields
        ) as s
    ),
    line_of_sight as (
        select
            segments.seg_id,
            segments.camera_id,
            segments.street_id,
            buildings.area_id as building_id,
            ST_Intersects(seg_line, buildings.geom) as inter
        from segments
        left join buildings
        on ST_Intersects(seg_line, buildings.geom)
    ),
    visible_street as (
        select
            camera_id,
            street_id,
            seg_id,
            not((inter is not null) and inter) as is_visible,
            building_id
        from line_of_sight
    )
select
    distinct
    street_id,
    camera_id
from visible_street
where is_visible;

select STRING_AGG(distinct(street_id::text), ',') from visible_streets_from_cam;

Editer du pbf avec osmium

Convertis en format opl (format textuelle, éditable)

osmium cat st_quentin.osm.pbf -f opl > st_quentin.opl

L'inverse

osmium cat st_quentin.opl -f pbf > st_quentin.osm.pbf

Avoir un diff

osmium diff st_quentin.osm.pbf merge.osm.pbf -f opl > diff.txt
cat diff.txt | grep "^+" # ajout
cat diff.txt | grep "^-" # suppression

Appliquer un fichier de changeset (attention écrase toute la relation ou tout le noeud)

osmium apply-changes st_quentin.osm.pbf osmChange.xml -o new.osm.pbf