2022/08/24 FOSS4G 2022 Academic Track 1 Analysis of the spatiotemporal accumulation process of Mapillary data and its relationship with OSM road data: A case study in Japan Toshikazu Seto* Ph.D. (tosseto) and Yuichiro Nishimura *: Associate Professor Department of Geography, Komazawa University OSGeo.JP (OSGeo Charter member) /OSMFJapan DOI: 10.5194/isprs-archives-XLVIII-4-W1-2022-403-2022 A02 KOMAZAWA UNIVERSITY Visual Identity Guidelines ϩΰλΠϓ ,ϚʔΫʴ࿨จϩΰλΠϓͷ૊Έ߹Θͤ ͸ɺ ࠨͷछͰ͢ɻ ԣ جຊܗͱ͠ɺ ༏ઌతʹ࢖༻͠·͢ɻ ԣ ϫϯϙΠϯτͳͲɺ ʮԣʯ ͕഑ஔ͠ʹ͍͘ ৔߹ʹ࢖༻͠·͢ɻ ॎ ॎܕαΠϯͳͲɺ ࡉ௕͍഑ஔʹ࢖༻͠·͢ɻ ඞͣϚελʔσʔλΛ࢖༻͍ͯͩ͘͠͞ɻ ࠨهҎ֎ͷ૊Έ߹ΘͤΛ࡞੒͠ͳ͍Ͱ ͍ͩ͘͞ɻ ॎ

2022/08/24 FOSS4G 2022 Academic Track 2 Overview of Mapillary Data in Japan Property Description Type Range of value key Keycode String 41,765,634 ca Cardinal points Real 0 – 360 degrees camera_make Device maker String 91 types camera_model Device name String 488 types captured_at Timestamp Date from 2014-01-01 to 2020-09-31 pano Panoramic shooting Boolean Yes: 5,413,030 No: 36,352,604 sequence_key Sequence code String 41,765,634 user_key Account code String 1,513 username Account name String 1,513 users Mapillary API (v. 3, 2017)

2022/08/24 FOSS4G 2022 Academic Track 3 Database Construction 1. Get data from Mapillary Search Image API (v. 3, 2017) ▶ GeoJSON（Zoom7 – total: 14h15m10s） 2. Convert to GeoJSON ▶ PostGIS ▶FlatGeobuf (.fgb) • PostGIS: 1.79-GB ▶ .fgb: 11.73-GB with 41,765,634 records • Reading & processing .fgb was three times faster than local PostGIS 3. Spatial Join with OSM road data attribution via QGIS • All OSM road data (.fgb): 3.2-GB with 8,313,281 records • the maximum search radius was set to 50 m of centerline 4. Output 17.6-GB point database in .fgb (with 23 attribution) + Aggregate with polygon for each municipality (232.2 MB; 1903 records with 32 attribution) + Aggregate with 1-km Grids (126.5 MB; 388,762 records with 20 attribution) • https://github.com/tossetolab/mapillary-analysis-japan

2022/08/24 FOSS4G 2022 Academic Track 4 • 1500 unique Mapillary contributors during the six years, with the top 10 users contributing approximately 90% of the images in Japan. • The proportion of Mapillary data compared to OSM road data has reached about 16% in some areas. • Approximately 40% of Mapillary related OSM roads have been updated since the Mapillary images were taken, which can help update OSM road data in Japan. Number of Mapillary postings per contributor OSM roads-Mapillary coverage rates Monthly Mapillary photos taken and number of contributed users.

2022/08/24 FOSS4G 2022 Academic Track 5 Last update date of OpenStreetMap road before and after Mapillary image taken by 1-km grid (unit: days)