OpenStreetMap

pangoSE's Diary

Missing direction of photos and layer with signs in OSC

Posted by pangoSE on 26 September 2018 in English.

I recently began contributing images via OSC. I’m using the app from Google Play updated on 21/8-18. Here is a sample of the direction being the same on all photos: http://openstreetcam.org/details/1292987/0/edit-osm (press iD to see the layer with directions shown).

The OSC plugin (v164) in JOSM (v14272) does not show direction, only blue dots.

Also my tracks have not yet been processed for signs or other data and no special layer with this information is avaliable to my knowledge.

Is Mapillary prefered over OSC because it includes directions of photos & this layer?

Discussion

Comment from alexkemp on 26 September 2018 at 11:34

Hi pangoSE

Mapillary shows Direction only if the uploaded photos include Direction within the meta-data. None of my Mapillary photos have a Direction component.

I use OSMTracker. My early Android mobile did not have Direction available, so no photos could ever have that included. However, my current mobile does have a Direction component, but OSMTracker never picks it up and attaches it to the JPEGs.

So, the questions are:–

  1. Does your camera provide a GPS:Direction component?
  2. Does the Application in the camera attach that GPS component to the JPEG?
  3. Does the web-app make use of that component?

Here is how to check:–

Camera

This only became apparent for me when I got a camera with the hardware to provide Direction. When GPS was turned ON in the camera it showed in the OSMTracker screen.

Photos

install ImageMagick (http://www.imagemagick.org/script/download.php), then use the identify tool that comes with ImageMagick. At the bottom of the -verbose screen are all the GPS components available within the JPEG (or TIFF) photo. Here is how to do it under Devuan/Debian/Ubuntu:–

:~$ sudo apt-get install imagemagick
:~$ identify -verbose osmtracker/2017-03-26_11-15-14.jpg | fgrep GPS
exif:GPSAltitude: 101000/1000
exif:GPSAltitudeRef: 240/100
exif:GPSDateStamp: 2017:03:26
exif:GPSInfo: 686
exif:GPSLatitude: 52/1, 59/1, 149408/10000
exif:GPSLatitudeRef: N
exif:GPSLongitude: 1/1, 5/1, 138908/10000
exif:GPSLongitudeRef: W
exif:GPSProcessingMethod: ASCII
exif:GPSTimeStamp: 10/1, 15/1, 8/1

Looking within the 2012 EXIF reference PDF I find the following:

•GPSTrackRef: Reference for direction of movement
•GPSTrack: Direction of movement
•GPSImgDirectionRef: Reference for direction of image
•GPSImgDirection: Direction of image

I’m not certain which of those four is used to provide GPS:Direction, but it is a touch academic since none of them are stored within any JPEGs produced with OSMTracker.

Comment from pangoSE on 30 September 2018 at 21:09

Thanks for the response.

Log in to leave a comment