SELECT row_to_json(fc)
  FROM
    (SELECT 'FeatureCollection' as type, array_to_json(array_agg(feats)) as features
      FROM
         (SELECT 'Feature' as type,
                 st_asgeojson(ST_TRANSFORM((gv).geom,4326))::json as geometry,
                 row_to_json((SELECT props FROM (SELECT (gv).val as value) as props )) as properties
            FROM
                (SELECT ST_PixelAsPolygons(
                    (SELECT l.rast FROM jbb2016 j

                    LEFT JOIN lerhaltskartan l ON
                    ST_INTERSECTS(j.geom,l.rast)

                    WHERE gid = 82523
                    )
                ) gv
          ) json
    ) feats
) fc;