New Dahua LPR

[wrybread]

Another funny detail about this camera is that you can't have a period in the FTP path.



I have websites on 3 different servers, with 3 different hosts, and every one of them has the top level domain (.com or .org or whatever) in the FTP path. But Dahua doesn't allow periods in the path, which means I can't upload from the camera to them... This thing is so half baked.

 

[biggen]

Its asking for the remote directory. You already gave it your top level "mysever.com" address. So now you need to feed it your path (e.g. /path/to/ftp).

 

[wrybread]

I know, but my point is that my server, like most servers, has the top level domain (and therefore a period) in the /path/to/ftp. For example on Dreamhost my website is at /home/myusername/mydomainname.com/whatever. I'm pretty sure AWS is the same way. I know there's a few hosts that don't have the top level domain in the FTP path, like Godaddy, but those are somewhat rare since it means that ftp user only has access to a single domain, and it's completely absurd to block the period, which is a legal character for directories. It's like deciding that the user can't have the letter A in their path.

And in the present form Dahua cameras can't upload to web accessible directories of at least half the web servers in the world, because of a silly oversight.

 

[wrybread]

And aha, there's hope for extracting the ALPR data without having to use the NVR (and I don't have enough faith in their software developers to give them another $450).

If FTP is enabled from the camera's Storage -> FTP, and ALPR is enabled, it uploads 3 images for every vehicle it sees: the full image, a crop of the vehicle, and a crop of the license plate. And the ALPR data is inside the JPEG comment tag of the full image (not the others).

I made a little Python script that walks the directory structure and extracts the data for any vehicle it finds, which works, but it's super kludgey, and still doesn't fix the problem of the bad APLR quality. But maybe I can tweak some settings after taking a break from this camera for awhile, ha.

 

[biggen]

I made a similar bash script to walk though the snapshot directory structure since the way it saved/named them was pretty terrible.

 

[wrybread]

Good idea. And yeah the file/folder structure is crazy. I could see using that for internal camera storage, but it's pretty lazy of Dahua to upload them that way.

 

[Wildcat_1]

@wrybread if you need assistance with the 7xxx over what I shared in the review and in the portions of other posts I made that @bigredfish and @EMPIRETECANDY shared then just reach out. Happy to help where I can

 

[wrybread]

Well I guess one question I have is: does it do a good job of alpr for you? And if you've used openalpr, how would you compare it?

I can't get it to produce usable alpr, and my lighting and angle are pretty good (see pics above).

 

[Wildcat_1]

@wrybread

Absolutely can pull great ALPR/ANPR from the 7xxx cams, that is one of their primary ways to shine. Setup, both in dialing in your FOV, image, lighting is critical though for ALPR/ANPR and more so than LPR/NPR as you need to give an environment in which the AI cam has enough time to a) detect a vehicle is the target on screen and then b) can auto detect the plates, vehicle details. You mention OpenALPR which is great but as I mentioned in my write up, you have to remember that OpenALPR is taking a stream and then has the advantage of applying Nvidia cloud based processing against it. Hence for those super hard to read plates (poor plate, challenging lighting) often times a 3rd party HW/SW AI platform will process slightly better as it has a) the luxury of not needing to do so in real-time (always a period of time after stream has been processed) and b) a huge amount of horsepower behind the processing.

With that said, the power of an ANPR/ALPR cam in conjunction with an NVR (5216 or higher for example) is the ability to build white/black lists and then trigger your security infrastructure against those. For example license plate 123 ABC is seen on 7xxx cam 1 and when it see’s it calls overview PTZ #2 to preset 1 where it is then waiting (at a choke point now) to intercept and track the vehicle identified. Other actions can be notifications in real-time when a specific vehicle or ‘type’ of vehicle moves through an area and you want it to capture + alert. In this second example think of an activity that has homeowners or LE looking for a blue car etc. All of this you get when combining an ANPR camera with an NVR hence the recommendation for using in conjunction as part of your security requirements. Add in Face Recognition cams and you then have truly powerful, on device, real-time capture solution (depending on your needs of course) that can tackle most needs BUT again need to be dialed in correctly.

That is why you’ll often see me recommend that depending on security needs (such as dark site where you cannot move streams off site) that you send your main stream to the NVR for processing and action as well as a sub-stream to OpenALPR or your tool of choice for secondary processing should you need it. Just remember these are 2 very different platforms. My recommendation if you had to choose 1 would be ANPR/ALPR + NVR.

I won't bore people and go into the other benefits of ANPR in conjunction with NVR such as metadata & tagged searches across cams etc as I already mentioned those in the post that @bigredfish & @EMPIRETECANDY linked back to earlier in this thread.

HTH. Take a look at my other posts in depth and if you need anything else feel free to DM me

 

[wrybread]

Interesting. I've had absolutely terrible results with it's ALPR. I'm now using OpenALPR with it, from exactly the same angle, and getting near 100%. With the Dahua's ALPR I'm lucky to get 1/3 correct.

Not being able to get the plate from this image is kind of crazy in my opinion:

Do you agree?

I get that OpenALPR has an advantage in processing, but if that camera can't even recognize the plate above, I question whether it's ALPR has any usefulness at all. I'm using it at a campground entrance, and capturing 1/3 of all the plates at best (optimal lighting conditions) just isn't useful. I guess there's some use cases where 1/3 accuracy is better than nothing but I can't think of any.

I'm using the latest firmware by the way.

As far as the NVR, I'm guessing it simply gets the ALPR data from the camera, as opposed to re-processing the images? If so, while it would certainly be nice to have the ability to search license plates (and it's pretty amazing that the camera can't do that natively), it's still the same bad data. For the low low price of $450!