Incorrect sequences due to long distance photos


#1

The photo sequences in Mapillary show the path taken and registered by the camera. This is useful to reproduce the same way the person who took the photos; however, if photos were taken in different journeys, but uploaded at the same time, it looks like a big jump in the sequence and a long straight line.

One example is the following: https://www.mapillary.com/app/user/ccossio?lat=1.883794516108722&lng=-76.29431367833219&z=6.236052121160821&pKey=Lyar4Sohc3l4gWs4NeYfyw&focus=map

The photographer took a photo in Sao Paulo, Brazil, and another in San Luis Potosi, Mexico. For these two photos, there is a straight line that crosses many countries, where no photos were taken.

I think Mapillary should detect this event, and do not show the line. For example, if the date between two photos is too distant, or if the difference between the coordinates of the photos is bigger than 100 meters. In these cases, Mapillary should cut the sequence.


#2

Hi, see the related question here http://forum.mapillary.io/t/how-to-break-an-existing-sequence-into-2-separate-sequences/720

They ‘clean up’ these ugly long distance lines once a week (or month) or so.

(I hope they reduce the distance to cut sequences to 100 meter as default)


#3

The sequence in question is several weeks old. @katrin wrote in the thread that they could split them manually.


#4

I listed this for manual splitting, hope to fix it soon. Thanks for reporting!


#5

Last time I travelled between South America and Europe I had problems with position and time in my action cam and GPS units taking a long time to update. This resulted in several lost (unusable) sequences. After a long travel, it is important that the units are given good time to stabilise the position and adjust clock before recording.


#6

Is this what’s clobbering the US map?

https://www.mapillary.com/app/?lat=39.9061973425643&lng=-83.9147537575393&z=6.6256984240855425&pKey=ITXTH5LAEOOHuOWxqFamew&focus=map


#7

I would say, that for each case it should be identified why the lines are there and it should be fixed acordingly.

  • Multiple trips uploaded as one: Split the sequence.
  • GPS started with a couple of images in the wrong place: Move or delete them.
  • GPS jumped quickly off path and found it again: Move or dele the images.

Just splitting will for the latter 2 cases give images in completely wrong locations. In GIS the main problem is always data quality, and we should try to make it as good as possible.

Hmm. I just looked at https://www.mapillary.com/app/?lat=38.34938299999999&lng=-85.04160138888892&z=17&pKey=Gin_oS4a-f3ldN9o5m15Ag&focus=photo by random. It looks like a sequence where a single point jumped a lot, but even though the point is connected to others, the forward and backward arrows are disabled. Like it is part of a sequence…but isn’t? Is this a Mapillary error?


#8

It looks like a lot of these have been cleaned up. Thank you to the people who worked on sorting it out…

https://www.mapillary.com/app/?lat=39.566252525467945&lng=-85.01291734417795&z=6.952121778397128&pKey=gwZ7V2hI5dA46b7cKESpGg&focus=map


#9

I have had some edits performed by a user called sequence_cut. I think it is an official bot that splits sequences.

In a perfect world a human should look at these, because there is often some iamges which are not placed correctly. But who has the time? At least it would require Mapillary to implement some functionality to allow the community to easier perform quality assurance.


#10

@tryl you are right, this is an automatic bot. I am not sure we will have the resources to build a manual review system for this anytime soon. I’m still interested to hear, though, which examples you have in mind with “often some images which are not placed correctly”?


#11

@katrin When I fix problems with my own photos, I have often seen that a few in the beginning of the sequence have been way off and some times the GPS has just jumped for off the correct location for a few images. If you just cut the sequence, you will have a few images that are placed in the completely wrong place.

But because you save the messages from the sequence_cut user, there is a record and if people want to fix it in the future, it is possible.

I can imagine that everybody have a lot of work to do, and I did not imagine any other fix at this point :smile:


#12

@angoca @katrin
Is this sequence a similar one? https://www.mapillary.com/map/im/VunoqQC-NtufWg57u-h92w
It’s is a straight line of good 360 photos, but unfotunately the GPS coordinates are totally incorrect.

same as: