[HN Gopher] OpenCV and the Wild Kingdom
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       OpenCV and the Wild Kingdom
        
       Author : zdw
       Score  : 62 points
       Date   : 2024-07-18 23:35 UTC (4 days ago)
        
 (HTM) web link (scottsexton.co)
 (TXT) w3m dump (scottsexton.co)
        
       | VoidWhisperer wrote:
       | Site doesn't actually seem to load (SSL protocol Error)
        
         | from-nibly wrote:
         | Loading now. (At least for me)
        
           | VoidWhisperer wrote:
           | Just figured it out was not loading because of my antivirus
           | (malwarebytes).. while virustotal doesn't flag the domain
           | name, the ip it is hosted on is flagged as malicious/a
           | trojan[0]. The IP is on Namecheap's ASN so evidently at some
           | point the ip was used by someone to host malicious files.
           | 
           | [0]: https://www.virustotal.com/gui/url/8d8ed17d3e28dc16fc10b
           | 6d76...
        
       | lloydjones wrote:
       | Excellent!
       | 
       | I wonder how difficult it would be to detect specific actions in
       | the video frames, like "cat eating food"?
        
         | pbmonster wrote:
         | A dynamically detected bounding box (cat) overlapping with a
         | predefined bounding box (bowl) would be less than 50 lines of
         | python if you use openCV. Discriminating raccoons and cats
         | would probably be another 50 lines if you use some pre-trained
         | ML model.
         | 
         | Adding an electric scale to the bowl would certainly cut down
         | the false positive rate you're going to get (from the cat, safe
         | to say the raccoon will always be eating if it overlaps the
         | bowl).
        
       | VMG wrote:
       | For those wondering, the "FLIR Boson" camera is around $900 on
       | eBay
        
         | stefan_ wrote:
         | If you don't want to pay quite that much, you can get cheap
         | thermal cameras from China e.g. from InfiRay. They just show up
         | as a UVC camera.
        
       | begueradj wrote:
       | I can't read the article. Getting below error:
       | 
       | "503 Service Unavailable
       | 
       | No server is available to handle this request. "
        
       | pmontra wrote:
       | https://archive.is/20240723031436/https://scottsexton.co/pos...
        
       | rurban wrote:
       | I've build a water fountain for my cats a year ago, with a simple
       | cheap motion sensor (3EUR AliExpress). They prefer running water
       | over everything, so it works great. The only real enemy,
       | neighbors black cat, is locked out.
        
       | hi_hi wrote:
       | I'm looking for a way to run a simple motion detector (as in
       | physical motion using a gryoscope device) and have this notify me
       | somehow that motion has occured. The bit I get stuck on is how to
       | enable connectivity so it can notify me from a remote position
       | with no access to wifi or wired network.
       | 
       | I would love for this thing to consume minimal power too, so I
       | only have to recharge the battery once per week (for example,
       | this might not be possible, or maybe something much better is
       | possible, i have no idea)
       | 
       | The most convenient option I can think of is a cheap smartphone
       | with 3g/4g data connection that can somehow integrate with the
       | motion sensor and enables me to write some code to send a
       | message.
       | 
       | There must be something better suited to this though. Thoughts
       | welcome.
        
         | hurtuvac78 wrote:
         | What's the distance you need to cover ? BLE use very little
         | power, is wireless, can go 100m or so, max.
        
         | buescher wrote:
         | The Nordic Thingy dev platform is available in both Bluetooth
         | Low Energy Long Range and cellular versions. It has everything
         | you need. More expensive than a cast-off cell phone for a one-
         | off though.
        
         | tastyfreeze wrote:
         | LoRa mesh network is another option.
         | 
         | I've considered BTLE and LoRa for a sensor network I have been
         | planning.
        
         | axegon_ wrote:
         | If I understand correctly, I feel like OpenCV and computer
         | vision is a huge overkill for something like that. Here are a
         | few thoughts:
         | 
         | 1. A microcontroller with a LoRa module and a motion sensor
         | will get you a long way and it will consume little to no power.
         | That said, you also need to make sure you have a device to
         | either read the signal or someone in a radius of 4 to 6km is
         | hosting a lorawan gateway. If not, I'm sure people will be
         | grateful if you set up one yourself - to my mind it's worth it
         | and I happen to be the only person that hosts one and covers my
         | area of the city. Just make sure you don't enable any of the
         | other gimmicks the microcontroller might come with - wifi,
         | bluetooth or whatever. For instance I have a bunch of these [1]
         | and they seem like they would do the trick for you if you pair
         | them with a motion sensor. I need to warn you though, the
         | documentation is appalling.
         | 
         | 2. If you do wanna go CV - you can but it will never be low
         | power and you will need to figure out some connectivity. If
         | it's a raspberry pi or some other SBC with GPIO, you could of
         | course hook up lora to it. As for the CV itself - opencv will
         | get you there or you could train a very small yolo-like neural
         | network - if you control the environment/lighting and they are
         | static, you only need a handful of sample images to train it
         | and you will get great accuracy. Like even something in the
         | very low double digits will do the trick. Imo that would be
         | overkill and your best bet is still the first option.
         | 
         | [1] https://www.lilygo.cc/en-bg/products/lora3
        
         | jononor wrote:
         | "asset tracker" is a good keyword to search for. Unless you
         | need very particular detection, there might be ofc the shelf
         | solutions that can work. "This thing is in motion" is often a
         | supported feature. Months of battery life is achievable, with
         | the right hardware. For cellular, the most modern standard is
         | NB-IoT. CAT LTE M1 also pretty good. Note: GPS tracker is also
         | a good searchword, as it is a common feature on (outdoor) asset
         | trackers, even though it might not be the most critical in your
         | intended application.
        
           | jononor wrote:
           | Check Teltonika TAT141, for an example. Supports
           | accelerometer wakeup. No affiliation, but have evaluated
           | their other products (BLE beacons and IOT gateways) before,
           | and got a good impression. https://teltonika-
           | gps.com/products/trackers/assets-workforce...
        
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       (page generated 2024-07-23 23:15 UTC)