Frigate+ score / Review discrepency

[jamesonuk]

I have a camera which is giving lots of false positives but I think they should have been filtered out.
Eg. when I look in Frigate+ tab I see

so only one entry for today with a score of 52%
but I am seeing lots of reviews

I don't have any global config around objects, thresholds, min scores etc. and the camera config is

Camera config

  xxx_camera_frigate:
    enabled: true
    ffmpeg:
      inputs:
        - path: rtsp://{FRIGATE_TAPO_USER}:{FRIGATE_TAPO_PWD}@xxx-tapo-camera.mikeynet/stream2
          roles:
            - detect
        - path: rtsp://127.0.0.1:8554/xxx_camera_frigate
          input_args: preset-rtsp-restream
          roles:
            - record
      output_args:
        record: preset-record-generic-audio-aac
    onvif:
      host: xxx-tapo-camera.mikeynet
      port: 2020
      user: '{FRIGATE_TAPO_USER}'
      password: '{FRIGATE_TAPO_PWD}'
    motion:
      mask:
        - 0,54,462,54,462,0,0,0,0,0

so I believe everything should be using defaults and this should therefore be using a threshold of 0.7 ? I am not seeing anything in Frigate + that is anywhere near 70% so I would have thought these should be excluded?? Am I missing something in the application of threshold or how the Frigate + entries are added?

[hawkeye217]

Have a look at the docs related to object scores: https://docs.frigate.video/configuration/object_filters

At some point, your object was detected with a score >= threshold, so the object was considered a true positive and the snapshot was created.

[hawkeye217]

For some clarity on how Frigate uses motion detection and object detection together, read this from the docs: https://docs.frigate.video/configuration/masks/#further-clarification

Also, you are probably aware, but for other readers of this thread, the detection pipeline is outlined here: https://docs.frigate.video/frigate/video_pipeline

I was thinking that the snapshot was the start of the detection but that can't be the case as the start of the detection in the link is frame 4 but the only way to get there is for the score to be over the threshold and the one shown isn't ?

Correct. For a snapshot to be taken, the object must be a true positive (it has scored above the threshold at some point already).

Another two frames of below min score would then drop the median below the threshold and detected object would not be true any more but what happens at this point in terms of events?

The tracked object's lifecycle ends, but not without caveats - depending on config settings like max_disappeared.

[jamesonuk]

Sorry for all the painful questions I would really love to get a deeper understanding and start contributing properly or at least help with testing and documentation. I am just not quite managing to join up the theory of the pipeline and what you see in the UI. My actual issue I will probably solve though Frigate+ but that is another task on my list...

Snapshots can be saved at any time during the detected objects lifecycle, each detection is considered and potentially calculated as the "best frame" for the object and that is the moment that is saved for the snapshot.

So can / will snapshots get updated if it determines a better frame or once the snapshot is taken is that then fixed for the whole of that detected objects lifecycle?

Once the object is a true positive the threshold / median score are not used to stop detecting the object, that is what the min_score is for. This is because objects like people can have periods of lower scores throughout their lifecycle such as when occluded by a hedge or getting into a car, this should not mean the person is gone / not a real person anymore.

So subject to some headroom to ensure it really has finished then once the score drops below min_score the object lifecycle ends and if that person appears again (they get back out car a minute later) then that will start a new lifecycle?

Taking this on to reviews I can see that the detected object lifecycle isn't quite the same as a review. You could have a second person enter the area and the original one leave and the review would continue until the second person also leaves (both lifecycles end because their score drops below min_score

I presume as in my case static objects also come into play here in that they are still under the same detected object lifecycle and Frigate is still tracking them but once it is decided they are static for long enough the review ends? So in my example there is basically one detected object lifecycle which is basically continuous but a review kicks in each time something triggers a change (most likely light levels ??)

[NickM-27]

So can / will snapshots get updated if it determines a better frame or once the snapshot is taken is that then fixed for the whole of that detected objects lifecycle?

snapshots can always be updated, as long as enough time has passed. By default this is 60 seconds and controlled with the best_image_timeout field

So subject to some headroom to ensure it really has finished then once the score drops below min_score the object lifecycle ends and if that person appears again (they get back out car a minute later) then that will start a new lifecycle?

yes

Taking this on to reviews I can see that the detected object lifecycle isn't quite the same as a review. You could have a second person enter the area and the original one leave and the review would continue until the second person also leaves (both lifecycles end because their score drops below min_score

a review will go on for as long as there are active objects in the camera frame (based on the reviews config) plus some padding.

I presume as in my case static objects also come into play here in that they are still under the same detected object lifecycle and Frigate is still tracking them but once it is decided they are static for long enough the review ends? So in my example there is basically one detected object lifecycle which is basically continuous but a review kicks in each time something triggers a change (most likely light levels ??)

right

[jamesonuk]

Updated the title based on what I actually wanted to know...

a review will go on for as long as there are active objects in the camera frame (based on the reviews config) plus some padding.

So active object is the same as an active detected object lifecycle?

Pennies are starting to drop. The one thing that is confusing me still (but isn't a big thing) is why Frigate+ screen is seemingly adding images many hours later. When I posted about noon the latest image on Frigate+ tab was 23:06 last night then in a reply about 14:00 I see three additional images going up to 23:37 and not I see another one from 3am this morning.

I presume this is just this best snapshot and it is keeping the old ones in Frigate+ but seems to be a very long lag of when they appear

[NickM-27]

The Frigate+ view will not show in progress objects, because those can not be submitted to Frigate+

A lot of this is cleaned up and more clear in 0.15, as Josh suggested