Python CLI tools : image direction NOT derived for Hero9 : my error or ...?

Hero9 black timelapse photo series uploaded using Python CLI tools ; notes on mapillary_tools/ at master · mapillary/mapillary_tools · GitHub , in section Derive image direction and Upload, state : “Derive image direction (image heading or camera angle) based on image latitude and longitude. If images are missing direction, the direction is derived automatically, if direction is present, it will be derived and overwritten only if the flag --interpolate directions is specified.”

Looking at Exif tags of pics taken with a camera with compass using ExifTool spot both a GPS Img Direction Ref, and a GPS Img Direction value; those entries are not present in pics saved by the Hero9 black : as it ought to be, as the Hero9 doesn’t have a built-in compass.

Looking at my sequence taken with the Hero9 on 11 Aug (uploaded 23 Aug) confirmed there is no img direction in the files, thus in my understanding image direction would be derived automatically - yet ‘fans’ on the Mapillary cookie policy use page all point due north, suggests image direction hasn’t (yet?) been derived.

Given that I have only recently started using the Python CLI tools : do I misunderstand the readme, or is there another cause, please?

Looking forward,

I upload from a Hero5 using the following command line options and get the direction interpolated correctly:

mapillary_tools process_and_upload --advanced --import_path . --user_name <USERNAME> --interpolate_directions --verbose --cutoff_distance 200 --cutoff_time 10 --duplicate_distance 1.0 --duplicate_angle 20

Like this one: Mapillary cookie policy use

@ralley ,

Thank you for the prompt response, my post is intended to find out whether either my understanding, or the readme, or the programming misses a trick.

Met vriendelijke groet (Dutch for ‘with friendely greeting’),

Reply to myself :
Exiftool doesn’t show image direction information in the GoPro Hero9 files; read-me suggests image direction will be inferred and added, but it wasn’t ; one needs to add --advanced and --interpolate_directions to the command line.
@tao : given that your name is in the list of contributors : could you please check what I found and clarify the text? (or let me know that I can’t read …)