Mapillary_tools : sequence processing issue

Hi There,

have noticed that some of my sequences are positioned incorrectly after upload.

Original images are all having correct EXIF data.

This error just pops up for some sequences.

Example

If you will download original and check it’s exif, you will see it is correct.

After investigation I have discovered that error occurs during mapillary_tools processing task.
For some reason geotag process is recording WRONG GPS metadata in mapillary tags.

Example:
Original EXIF:


Mapillary tag after processing:
image
As you can see - latitude gets broken and reported incorrectly.

source file
MT 0.6.0 processed file

Very strange… and very odd.
Just tried Desktop uploader and legacy MT 0.5 - same issue

Source files (original)

Processing with Desktop uploader (wrong placement):

Processing with MT 0.6.0 and uploading (wrong placement):
Sequence

Original placement as per EXIF tags (CORRECT)

I suspect a compatibility issue with Exif data
image

EXIF stores lat/lon as groups of three fractions. In this case the three fractions are 53/1, 0/0, 105/1024 (deg, min, sec). So there’s a division by zero in the original EXIF that’s blowing things up.

Looks to me like the camera/writing application is in the wrong, rather than the Mapillary uploader.

2 Likes

yes, you are right , the issue is on video processing script/python module, will have closer look `next week.

issue was rectified, it was a bug (compatibility issue) on the source exif side indeed.