yellow and blue boxes appearing but no event stored

[KonTiki1957]

Hi to everyone, I wrote on this section instead of the issue section because I'm quite sure it's not an issue but a poor understanding on my part of the configuration settings.

My conf Rpi4, HA on docker, dahua cameras (unfortunately no coral yet). Well while struggling with reliable configurations for my 4 cameras I noticed on the camera stream that although the object was correctly identified with a relatively high score and yellow/blue boxes (btw what do the blue boxes mean?) neither the event was stored nor I got any telegram message, what could this mean? I'm trying to reduce as much as possible the cpu load so I configured motion masks and object masks but I deleted the latter to see if the issue depended on them with no luck. On a similar machine I have doods running, which I had previously modified to reduce the cpu load in a way that the camera motion detector triggers a snapshot and then doods calmly analyzes the image instead of continuously monitor the stream, and the same image gets normally identified so I think it's a settings problem in my frigate instance. Anyone willing to help me understand which configuration settings may be responsible for this? Would it be possible to tweak frigate in a similar way to trigger it's analysis only upon motion detection by the camera software and thus reducing cpu load? My configuration follows and as always thank you to the people developing this addon :-)
camera:
est:
ffmpeg:
inputs:
- path: rtsp://user:[email protected]:554/cam/realmonitor?channel=1&subtype=1
roles:
- detect
- clips
rtmp:
enabled: False
snapshots:
enabled: True
bounding_box: True
timestamp: True
retain:
default: 3
clips:
enabled: True
pre_capture: 5
post_capture: 5
objects:
- person
- cat
- dog
retain:
default: 3
objects:
person: 3
width: 640
height: 480
fps: 5
objects:
track:
- person
- cat
- dog
motion:
mask:
- 528,151,421,141,314,72,287,0,640,0,640,254
- 243,0,264,71,293,135,369,195,386,254,507,290,556,168

[KonTiki1957]

well I may have an answer to my own question. Since the cameras are not very close to the scene I tried to set a lower value to min_area and so far the issue seems to have gone away ... but referring to this setting is anybody able to explain how exactly those two values (min_area, max_area) have to be computed?