Best settings for Sentry? Improvements possible?

hb020

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Hi, just starting with Sentry. After having read through most of the threads on Sentry here, I have come to some conclusions. Since this is my first impression, please correct me if I'm wrong.
  1. Upon trigger, BI sends exactly 1 downsized image to Sentry (in the "cloud") for analysis. The transport is encrypted (it would be outrageous if that was not the case), but I have a very strong suspicion Sentry decrypts the image for person detection.
    Question 1: Or has BI already done the first steps of the inference, thereby "obfuscating" the image a bit?
  2. One MUST configure BI correctly for Sentry to work. And I haven't found a "how to set up" list. The following is a compilation of what I saw in various posts. AFAIK, crucial are:
    1. enable "motion sensor"
    2. set correct object size, contrast. This is depending on your camera setup (angle, distance..). Remark: it is a shame BI does not allow perspective controls, as some others do. It would help with high vantage points.
    3. set correct "min. duration". This determines the image that is sent to Sentry. This setting is tricky, and very much depends on "expected speed of the subject to be detected". Remark: But the problem is: you do not know the speed of the subject in advance. This is I think the weak point. Sentry should get more than 1 image.
      Question 2: is there any chance you can send more than 1 image per alert? Like 1 per frame (as others do)? That would improve detection quality a lot I think.
    4. do not highlight motion (as Sentry gets the "enhanced" image). Remark: That is a bit of a shame, BI could also just send a non-"enhanced" image, while keeping the rectangle and motion in the alert clips.
    5. set object detection. Especially "object travels" serves almost the same purpose as "minimum duration" (but is better suited IMHO), and "Reset detector".
    6. set Zones and hotspot: helps excluding non wanted zones.
    7. and the other settings in the "motion sensor" screen.
      Question 3: Is this all? Or are there other settings to be considered?
My questions:
  1. Am I right in my assumptions? If not, please correct me. I just want to understand.
  2. See the 3 questions above.
  3. I know the answer ("no"), but I still try: Is there any chance Sentry could work in the edge (i.e.: locally)? Some of your competitors allow that. And with GPU acceleration and the EdgeTPU being rather accessible, and the models getting better and better (I personally find the quality of the object classification via MobileNetv2 on EdgeTPU becoming rather good considering the amount of Watts it takes), it is not out of reach of the typical BI users.
 
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varghesesa

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Great summary. We do have a setup guide.

1. Correct. We are planning on ingesting 3 frames per clip down the road to make the integration less brittle (MAKE time, +1s, +2s)
2.1. Correct. Sentry AI piggy=backs off of BI's motion sensor.
2.2. The motion settings for contrast and object size are really to get motion detection working correctly on BI (regardless of Sentry). Since Sentry is dependent on BI motion, Sentry is dependent on BI motion settings being configured correctly.
2.3. Correct. Min. duration = MAKE time. As stated above, planning on pulling 3 frames per motion clip to make integration less brittle.
2.4. Good idea! Regardless of user settings, BI should be able to send the original image. I will add to roadmap.
2.5. Object travels may or may not be significant. I'm still trying to get a better understanding on how to set it. I noticed on a high resolution camera (1080p), when I place it far back from the front door, it provides the right sensitivity to send an alert when needed. However, when I place the same camera in a small area, like a bedroom and the field of view is much closer, then I need to move quite a bit more in the camera frame in order to trigger motion. Much less sensitive. So there are times when you will need to play with "object travels". I hope to provide some guidance in my next webinar.
2.6. There are users that use Zones & Hot spots to reduce false alerts due to shadows, wind or the pet cat roaming around by the front door. In those cases, simply turning off zones & hot spots & turning on Sentry will work and we are fairly accurate at detecting human activity. However, there are occasions where homeowners reside on a busy street or sidewalk. In those cases, creating a zone of interest is of benefit so you only get alerts on people approaching your door and not just walking on the sidewalk.
2.7. I do not use any of the other settings.

Further questions:
3. We just don't have the engineering resources right now to deliver an on-prem solution. Some users request on-prem solutions for privacy concerns. We are planning to alleviate that fear by providing a customer portal this year so users can see exactly which images are being sent to Sentry for processing with the option to delete images. We hope to assure users through transparency until we can deliver an on-prem version.

-- Sam from Sentry
 

hb020

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Thanks, will look in the setup guide.

We are planning on ingesting 3 frames per clip down the road to make the integration less brittle (MAKE time, +1s, +2s)
If you could add -1s also, that would be great. Sometimes the objects move fast, so T0 sometimes means "leaving".

I must say that I have a load of false positives on trees. If you want images, I can send you them.
 

varghesesa

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If you don't mind submitting a ticket to support@smarthomesentry.com with sentry id & camera name, we can investigate further.

Our AI is supposed to get smarter over time and not alert on trees. I'm thinking another good use case for activating zones or the new invert zones function is to mark off the bushes/trees as an area of non-interest. Active zones work well with Sentry. Have not played with invert... but I would imagine that logic would work fine as well.

-- Sam from Sentry
 
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