GeoJSON from EXIF

exiftool -n -g -json \
  -imagewidth \
  -imageheight \
  -composite:gpslatitude \
  -composite:gpslongitude \
  *jpg \
  | jq --compact-output --arg urlBase http://mysite.net/myphotos/ \
  '{
    "type": "FeatureCollection",
    "features": 
      map( {
        "type": "Feature", 
        "properties": {"url": [$urlBase,.SourceFile] | add,
        "width": .File.ImageWidth,
        "height": .File.ImageHeight,},
        "geometry": {
          "type": "Point",
          "coordinates": [ .Composite.GPSLongitude, .Composite.GPSLatitude]}
      } )
  }' \
  > data.json