PTZ autotracking with multiple people?

[hawkeye217]

For those of you who have an autotracking PTZ from Andy, what have you observed as far as the default behavior when multiple people to be tracked are in the frame? Will the camera zoom and attempt to keep both of the people in the frame? Will it only focus on the closest or furthest one? Or on the one it finds first?

Curious if anyone has any thoughts or even example videos on what they've seen the cameras do!

 

[wittaj]

It depends on what you set for object track size. If you make it too large it will be one person and usually the first one it sees.

Make track size smaller and you can usually get a group if they are close together.

Here is a good example that shows using spotter cams but shows more than one.

Another "That camera is following me" clip

At least they had a good chuckle over it....

ipcamtalk.com

 

[hawkeye217]

Definitely helpful @wittaj. I wonder what would have happened if the two people had appeared at the same time but at different ends of the frame... The spotter cam would have picked them both up, but maybe it's a tossup as to which one the ptz would have started tracking?

 

[bigredfish]

My experience with 4 PTZs is that they will track the first trigger object until they lose track or are called away by a spotter cam or a time limit. If in a group, the PTZ is still only tracking one target, if the group happens to be close enough together, and the track target size is set relatively small you will see more of the group as mentioned above. But its still tracking a single specific target.

These two clips clearly show that the PTZ has lock on a target and is not confused by other possible matching targets even when they are closer.

View attachment HOA Ent_ch1_20201116151428_20201116151504.mp4

















View attachment HOA Entr_ch1_20200927104112_20200927104207.mp4

 

[hawkeye217]

Thanks for those videos, @bigredfish. Exactly what I was looking for.

Would that be the ideal behavior of an autotracking PTZ?

In your first video, would you rather have had the camera back off of the man with the hat to get the two bike riders in the frame as well, and then once they exit the frame, have the cam zoom back in on the man with the hat? In other words, if the camera was set up for human detection, would it be preferable to have all of the humans in the frame, or only the first one that it found and began to track?

I suppose it's a tough question to answer because every situation would be different.

 

[bigredfish]

Exactly. Every scene and every scenario would be different. Its impossible with current technology that I've seen.

I suppose when AI becomes a bit smarter, we could set rules that say something like, "if you're tracking a guy with a big hat or a black car, and a blonde woman under 30, wearing a short dress with great legs passes within the FOV, stop tracking hat guy and track the blonde". But I think we're aways off. Even then, think of all the possible scenarios, what if a redhead wearing shorts crosses paths with the blonde?

I think before we get there, we'll see a greater selection of AI targets. Dogs, cats, UPS trucks, Aliens, each can have a specific signature. But deciding when to break track and chase something else is I think a whole other level

 

[hawkeye217]

Right

Well, I'm working on adding "poor man's autotracking" features to Frigate to do object tracking with any PTZ. Frigate is already really fast at tracking objects (not just humans and vehicles), and it doesn't seem like it would be too far fetched to get something working.

 

[bigredfish]

I mean really we're already doing simple "prioritization" of targets right? Dahua and HiK give us the ability to choose or prioritize Human, Vehicle, Other. So expanding that list isn't at all far fetched. I think some of their higher end stuff already does this. So the next step is adding simple If/And boolean logic right? past that it gets complicated and Im at the edge of my noodle power.

 

[hawkeye217]

For sure. The way that the autotracking PTZs work now along with BI and spotter cams seem to be a great solution for most "prosumers".