Unlocking the Secrets of Snapchat Filters: How Do Apps Track Speed?

In summary, the conversation discussed the use of Snapchat filters that show the speed of the phone at the time a picture was taken. The method for tracking speed in running apps was also brought up, with some participants speculating that GPS is used. However, there were doubts about the accuracy of GPS and others suggested the use of accelerometers. It was concluded that while GPS may not be completely accurate, it is still a useful tool for tracking speed over a longer distance. The original poster was specifically interested in finding the instantaneous speed at the time a picture was taken, but it was mentioned that this may be calculated using a multi-reading or decaying average.
  • #1
guitarphysics
241
7
I don't know if many of you have snapchat, but it's basically an app for taking pictures and sending them to others. Something you can do is add a filter that shows what speed your phone was going while the picture was taken.. How is this done? Or, more generally, how do things like running apps track speed?
I'm guessing GPS, but the reason I'm doubtful is that usually my phone's GPS gives me my location to an accuracy of around [itex]\pm [/itex]10 meters, and that's after I've let the GPS settle down for a minute or so. So I don't know if that's the way they do it. Anybody know, or have any ideas?
 
Physics news on Phys.org
  • #2
guitarphysics said:
I don't know if many of you have snapchat, but it's basically an app for taking pictures and sending them to others. Something you can do is add a filter that shows what speed your phone was going while the picture was taken.. How is this done? Or, more generally, how do things like running apps track speed?
I'm guessing GPS, but the reason I'm doubtful is that usually my phone's GPS gives me my location to an accuracy of around [itex]\pm [/itex]10 meters, and that's after I've let the GPS settle down for a minute or so. So I don't know if that's the way they do it. Anybody know, or have any ideas?
Based on the replies in this thread, it looks like it done using various tools (including GPS) and isn't very accurate.
How can I find the velocity using accelerometers only?
 
  • #3
It's GPS. And while it is true that it isn't as accurate as one would hope, over a long walk/run, the error becomes negligible. For example, if you run 3k and the distance is off by 10m, that's only 1/3 of 1%.
 
  • #4
russ_watters said:
It's GPS. And while it is true that it isn't as accurate as one would hope, over a long walk/run, the error becomes negligible. For example, if you run 3k and the distance is off by 10m, that's only 1/3 of 1%.
The OP was looking for instaneous speed at the time that a picture was taken.
 
  • #5
Borg said:
The OP was looking for instaneous speed at the time that a picture was taken.
Fair enough: I don't know the algorithm by which it calculates "instantaenous speed", but suffice to say, is isn't instantaneous speed. Just a guess, but I suspect it uses a multi-reading average or decaying average.
 

1. How do Snapchat filters track speed?

Snapchat filters track speed by using the accelerometer and gyroscope sensors in your phone. These sensors measure changes in motion and orientation, allowing the app to calculate your speed and apply the appropriate filter.

2. Can Snapchat filters accurately track speed?

Yes, Snapchat filters can accurately track speed within a certain range. However, factors such as phone placement and movement can affect the accuracy of the speed measurement.

3. How do Snapchat filters know which filter to apply based on speed?

Each filter has a pre-set speed range associated with it. When the app detects your speed within a certain range, it will automatically apply the corresponding filter.

4. Can Snapchat filters track speed in all types of transportation?

No, Snapchat filters are designed to track speed based on the user's movement. This means they may not work accurately in vehicles or other forms of transportation where the user is not physically moving.

5. Are there any privacy concerns with Snapchat filters tracking speed?

There are no major privacy concerns with Snapchat filters tracking speed. The app only uses the speed data to apply filters and does not store or share this information with any third parties. However, users should always be cautious when sharing personal information on social media platforms.

Similar threads

  • General Discussion
2
Replies
41
Views
4K
Replies
19
Views
4K
  • Mechanics
Replies
5
Views
2K
  • Atomic and Condensed Matter
Replies
4
Views
1K
  • Electrical Engineering
Replies
15
Views
2K
Replies
69
Views
10K
Replies
5
Views
920
Replies
10
Views
2K
Replies
15
Views
2K
  • Calculus and Beyond Homework Help
Replies
3
Views
1K
Back
Top